Safe Haskell	Safe-Inferred
Language	Haskell2010

Rel8

Contents

Database types
- DBType
  - Deriving-via helpers
  - TypeInformation
- The DBType hierarchy
Tables and higher-kinded tables
Expressions
Queries
IO
Running statements

Synopsis

class NotNull a => DBType a where
- typeInformation :: TypeInformation a
newtype JSONEncoded a = JSONEncoded {
- fromJSONEncoded :: a
}
newtype JSONBEncoded a = JSONBEncoded {
- fromJSONBEncoded :: a
}
newtype ReadShow a = ReadShow {
- fromReadShow :: a
}
newtype Composite a = Composite a
class (DBType a, HKDable a) => DBComposite a where
- compositeFields :: HKD a Name
- compositeTypeName :: String
compose :: DBComposite a => HKD a Expr -> Expr a
decompose :: forall a. DBComposite a => Expr a -> HKD a Expr
newtype Enum a = Enum a
class (DBType a, Enumable a) => DBEnum a where
- enumValue :: a -> String
- enumTypeName :: String
class (Generic a, GEnumable (Rep a)) => Enumable a
data TypeInformation a = TypeInformation {
- encode :: a -> PrimExpr
- decode :: Value a
- typeName :: String
}
mapTypeInformation :: (a -> b) -> (b -> a) -> TypeInformation a -> TypeInformation b
parseTypeInformation :: (a -> Either String b) -> (b -> a) -> TypeInformation a -> TypeInformation b
class DBType a => DBSemigroup a where
- (<>.) :: Expr a -> Expr a -> Expr a
class DBSemigroup a => DBMonoid a where
- memptyExpr :: Expr a
class DBType a => DBNum a
class (DBNum a, DBOrd a) => DBIntegral a
class DBNum a => DBFractional a
class DBFractional a => DBFloating a
class HTable (GColumns t) => Rel8able t
type KRel8able = Rel8able
type family Column context a where ...
type family HADT context t where ...
type family HEither context = either | either -> context where ...
type family HMaybe context = maybe | maybe -> context where ...
type family HList context = list | list -> context where ...
type family HNonEmpty context = nonEmpty | nonEmpty -> context where ...
type family HNull context = maybe | maybe -> context where ...
type family HThese context = these | these -> context where ...
type family Lift context a where ...
class (HTable (Columns a), context ~ Context a, a ~ Transpose context a) => Table context a | a -> context where
- type Columns a :: HTable
- type Context a :: Context
- type FromExprs a :: Type
- type Transpose (context' :: Context) a :: Type
- toColumns :: a -> Columns a context
- fromColumns :: Columns a context -> a
- fromResult :: Columns a Result -> FromExprs a
- toResult :: FromExprs a -> Columns a Result
class HTable t
class (Table from a, Table to b, Congruent a b, b ~ Transpose to a, a ~ Transpose from b) => Transposes from to a b | a -> from, b -> to, a to -> b, b from -> a
class AltTable f where
- (<|>:) :: Table Expr a => f a -> f a -> f a
class AltTable f => AlternativeTable f where
- emptyTable :: Table Expr a => f a
class Table Expr a => EqTable a where
- eqTable :: Columns a (Dict (Sql DBEq))
(==:) :: forall a. EqTable a => a -> a -> Expr Bool
(/=:) :: forall a. EqTable a => a -> a -> Expr Bool
class EqTable a => OrdTable a where
- ordTable :: Columns a (Dict (Sql DBOrd))
(<:) :: forall a. OrdTable a => a -> a -> Expr Bool
(<=:) :: forall a. OrdTable a => a -> a -> Expr Bool
(>:) :: forall a. OrdTable a => a -> a -> Expr Bool
(>=:) :: forall a. OrdTable a => a -> a -> Expr Bool
ascTable :: forall a. OrdTable a => Order a
descTable :: forall a. OrdTable a => Order a
greatest :: OrdTable a => a -> a -> a
least :: OrdTable a => a -> a -> a
lit :: forall exprs a. Serializable exprs a => a -> exprs
bool :: Table Expr a => a -> a -> Expr Bool -> a
case_ :: Table Expr a => [(Expr Bool, a)] -> a -> a
castTable :: Table Expr a => a -> a
data MaybeTable context a
maybeTable :: Table Expr b => b -> (a -> b) -> MaybeTable Expr a -> b
($?) :: forall a b. Sql DBType b => (a -> Expr b) -> MaybeTable Expr a -> Expr (Nullify b)
nothingTable :: Table Expr a => MaybeTable Expr a
justTable :: a -> MaybeTable Expr a
isNothingTable :: MaybeTable Expr a -> Expr Bool
isJustTable :: MaybeTable Expr a -> Expr Bool
fromMaybeTable :: Table Expr a => a -> MaybeTable Expr a -> a
optional :: Query a -> Query (MaybeTable Expr a)
catMaybeTable :: MaybeTable Expr a -> Query a
traverseMaybeTable :: (a -> Query b) -> MaybeTable Expr a -> Query (MaybeTable Expr b)
aggregateMaybeTable :: (exprs -> aggregates) -> MaybeTable Expr exprs -> MaybeTable Aggregate aggregates
nameMaybeTable :: Name (Maybe MaybeTag) -> a -> MaybeTable Name a
data EitherTable context a b
eitherTable :: Table Expr c => (a -> c) -> (b -> c) -> EitherTable Expr a b -> c
leftTable :: Table Expr b => a -> EitherTable Expr a b
rightTable :: Table Expr a => b -> EitherTable Expr a b
isLeftTable :: EitherTable Expr a b -> Expr Bool
isRightTable :: EitherTable Expr a b -> Expr Bool
keepLeftTable :: EitherTable Expr a b -> Query a
keepRightTable :: EitherTable Expr a b -> Query b
bitraverseEitherTable :: (a -> Query c) -> (b -> Query d) -> EitherTable Expr a b -> Query (EitherTable Expr c d)
aggregateEitherTable :: (exprs -> aggregates) -> (exprs' -> aggregates') -> EitherTable Expr exprs exprs' -> EitherTable Aggregate aggregates aggregates'
nameEitherTable :: Name EitherTag -> a -> b -> EitherTable Name a b
data TheseTable context a b
theseTable :: Table Expr c => (a -> c) -> (b -> c) -> (a -> b -> c) -> TheseTable Expr a b -> c
thisTable :: Table Expr b => a -> TheseTable Expr a b
thatTable :: Table Expr a => b -> TheseTable Expr a b
thoseTable :: a -> b -> TheseTable Expr a b
isThisTable :: TheseTable Expr a b -> Expr Bool
isThatTable :: TheseTable Expr a b -> Expr Bool
isThoseTable :: TheseTable Expr a b -> Expr Bool
hasHereTable :: TheseTable Expr a b -> Expr Bool
hasThereTable :: TheseTable Expr a b -> Expr Bool
justHereTable :: TheseTable context a b -> MaybeTable context a
justThereTable :: TheseTable context a b -> MaybeTable context b
alignMaybeTable :: MaybeTable Expr a -> MaybeTable Expr b -> MaybeTable Expr (TheseTable Expr a b)
alignBy :: (a -> b -> Expr Bool) -> Query a -> Query b -> Query (TheseTable Expr a b)
keepHereTable :: TheseTable Expr a b -> Query (a, MaybeTable Expr b)
loseHereTable :: TheseTable Expr a b -> Query b
keepThereTable :: TheseTable Expr a b -> Query (MaybeTable Expr a, b)
loseThereTable :: TheseTable Expr a b -> Query a
keepThisTable :: TheseTable Expr a b -> Query a
loseThisTable :: TheseTable Expr a b -> Query (MaybeTable Expr a, b)
keepThatTable :: TheseTable Expr a b -> Query b
loseThatTable :: TheseTable Expr a b -> Query (a, MaybeTable Expr b)
keepThoseTable :: TheseTable Expr a b -> Query (a, b)
loseThoseTable :: TheseTable Expr a b -> Query (EitherTable Expr a b)
bitraverseTheseTable :: (a -> Query c) -> (b -> Query d) -> TheseTable Expr a b -> Query (TheseTable Expr c d)
aggregateTheseTable :: (exprs -> aggregates) -> (exprs' -> aggregates') -> TheseTable Expr exprs exprs' -> TheseTable Aggregate aggregates aggregates'
nameTheseTable :: Name (Maybe MaybeTag) -> Name (Maybe MaybeTag) -> a -> b -> TheseTable Name a b
data ListTable context a
listTable :: Table Expr a => [a] -> ListTable Expr a
($*) :: Projecting a (Expr b) => Projection a (Expr b) -> ListTable Expr a -> Expr [b]
nameListTable :: Table Name a => a -> ListTable Name a
many :: Table Expr a => Query a -> Query (ListTable Expr a)
manyExpr :: Sql DBType a => Query (Expr a) -> Query (Expr [a])
catListTable :: Table Expr a => ListTable Expr a -> Query a
catList :: Sql DBType a => Expr [a] -> Query (Expr a)
data NonEmptyTable context a
nonEmptyTable :: Table Expr a => NonEmpty a -> NonEmptyTable Expr a
($+) :: Projecting a (Expr b) => Projection a (Expr b) -> NonEmptyTable Expr a -> Expr (NonEmpty b)
nameNonEmptyTable :: Table Name a => a -> NonEmptyTable Name a
some :: Table Expr a => Query a -> Query (NonEmptyTable Expr a)
someExpr :: Sql DBType a => Query (Expr a) -> Query (Expr (NonEmpty a))
catNonEmptyTable :: Table Expr a => NonEmptyTable Expr a -> Query a
catNonEmpty :: Sql DBType a => Expr (NonEmpty a) -> Query (Expr a)
data NullTable context a
nullableTable :: (Table Expr a, Table Expr b) => b -> (a -> b) -> NullTable Expr a -> b
nullTable :: Table Expr a => NullTable Expr a
nullifyTable :: a -> NullTable Expr a
isNullTable :: Table Expr a => NullTable Expr a -> Expr Bool
isNonNullTable :: Table Expr a => NullTable Expr a -> Expr Bool
catNullTable :: Table Expr a => NullTable Expr a -> Query a
nameNullTable :: a -> NullTable Name a
toNullTable :: Table Expr a => MaybeTable Expr a -> NullTable Expr a
toMaybeTable :: Table Expr a => NullTable Expr a -> MaybeTable Expr a
type NameADT t = GGName 'Sum (ADTRep t) (ADT t Name)
nameADT :: forall t. ConstructableADT t => NameADT t
data ADT t context
class (Generic (Record (t Result)), HTable (GColumnsADT t), GSerializeADT TSerialize TColumns (Eval (ADTRep t Expr)) (Eval (ADTRep t Result))) => ADTable t
type DeconstructADT t r = GGDeconstruct 'Sum (ADTRep t) (ADT t Expr) r
deconstructADT :: forall t r. (ConstructableADT t, Table Expr r) => DeconstructADT t r
type BuildADT t name = GGBuild 'Sum name (ADTRep t) (ADT t Expr)
buildADT :: forall t name. BuildableADT t name => BuildADT t name
type ConstructADT t = forall r. GGConstruct 'Sum (ADTRep t) r
constructADT :: forall t. ConstructableADT t => ConstructADT t -> ADT t Expr
type AggregateADT t = forall r. GGAggregate 'Sum (ADTRep t) r
aggregateADT :: forall t. ConstructableADT t => AggregateADT t -> ADT t Expr -> ADT t Aggregate
data HKD a f
class (Generic (Record a), HTable (GColumns (HKD a)), KnownAlgebra (GAlgebra (Rep a)), Eval (GGSerialize (GAlgebra (Rep a)) TSerialize TColumns (Eval (HKDRep a Expr)) (Eval (HKDRep a Result))), GRecord (GMap (TColumn Result) (Rep a)) ~ Rep (Record a)) => HKDable a
type BuildHKD a name = GGBuild (GAlgebra (Rep a)) name (HKDRep a) (HKD a Expr)
buildHKD :: forall a name. BuildableHKD a name => BuildHKD a name
type ConstructHKD a = forall r. GGConstruct (GAlgebra (Rep a)) (HKDRep a) r
constructHKD :: forall a. ConstructableHKD a => ConstructHKD a -> HKD a Expr
type DeconstructHKD a r = GGDeconstruct (GAlgebra (Rep a)) (HKDRep a) (HKD a Expr) r
deconstructHKD :: forall a r. (ConstructableHKD a, Table Expr r) => DeconstructHKD a r
type NameHKD a = GGName (GAlgebra (Rep a)) (HKDRep a) (HKD a Name)
nameHKD :: forall a. ConstructableHKD a => NameHKD a
type AggregateHKD a = forall r. GGAggregate (GAlgebra (Rep a)) (HKDRep a) r
aggregateHKD :: forall a. ConstructableHKD a => AggregateHKD a -> HKD a Expr -> HKD a Aggregate
data TableSchema names = TableSchema {
- name :: String
- schema :: Maybe String
- columns :: names
}
data Name a
namesFromLabels :: Table Name a => a
namesFromLabelsWith :: Table Name a => (NonEmpty String -> String) -> a
data Expr a
class (constraint (Unnullify a), Nullable a) => Sql constraint a
litExpr :: Sql DBType a => a -> Expr a
unsafeCastExpr :: Sql DBType b => Expr a -> Expr b
unsafeLiteral :: String -> Expr a
class (Nullable a, IsMaybe a ~ 'False) => NotNull a
class Nullable' (IsMaybe a) a => Nullable a
class IsMaybe a ~ IsMaybe b => Homonullable a b
null :: DBType a => Expr (Maybe a)
nullify :: NotNull a => Expr a -> Expr (Maybe a)
nullable :: Table Expr b => b -> (Expr a -> b) -> Expr (Maybe a) -> b
isNull :: Expr (Maybe a) -> Expr Bool
isNonNull :: Expr (Maybe a) -> Expr Bool
mapNull :: DBType b => (Expr a -> Expr b) -> Expr (Maybe a) -> Expr (Maybe b)
liftOpNull :: DBType c => (Expr a -> Expr b -> Expr c) -> Expr (Maybe a) -> Expr (Maybe b) -> Expr (Maybe c)
catNull :: Expr (Maybe a) -> Query (Expr a)
coalesce :: Expr (Maybe Bool) -> Expr Bool
class DBType a => DBEq a
true :: Expr Bool
false :: Expr Bool
not_ :: Expr Bool -> Expr Bool
(&&.) :: Expr Bool -> Expr Bool -> Expr Bool
and_ :: Foldable f => f (Expr Bool) -> Expr Bool
(||.) :: Expr Bool -> Expr Bool -> Expr Bool
or_ :: Foldable f => f (Expr Bool) -> Expr Bool
(==.) :: forall a. Sql DBEq a => Expr a -> Expr a -> Expr Bool
(/=.) :: forall a. Sql DBEq a => Expr a -> Expr a -> Expr Bool
(==?) :: DBEq a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
(/=?) :: DBEq a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
in_ :: forall a f. (Sql DBEq a, Foldable f) => Expr a -> f (Expr a) -> Expr Bool
boolExpr :: Expr a -> Expr a -> Expr Bool -> Expr a
caseExpr :: [(Expr Bool, Expr a)] -> Expr a -> Expr a
like :: Expr Text -> Expr Text -> Expr Bool
ilike :: Expr Text -> Expr Text -> Expr Bool
class DBEq a => DBOrd a
(<.) :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr Bool
(<=.) :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr Bool
(>.) :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr Bool
(>=.) :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr Bool
(<?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
(<=?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
(>?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
(>=?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool
leastExpr :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr a
greatestExpr :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr a
class Function arg res
function :: Function args result => String -> args -> result
nullaryFunction :: Sql DBType a => String -> Expr a
binaryOperator :: Sql DBType c => String -> Expr a -> Expr b -> Expr c
data Query a
showQuery :: Table Expr a => Query a -> String
type Projection a b = Transpose (Field a) a -> Transpose (Field a) b
class Projectable f where
- project :: Projecting a b => Projection a b -> f a -> f b
class Biprojectable p where
- biproject :: (Projecting a b, Projecting c d) => Projection a b -> Projection c d -> p a c -> p b d
class (Transposes (Context a) (Field a) a (Transpose (Field a) a), Transposes (Context a) (Field a) b (Transpose (Field a) b)) => Projecting a b
data Field table a
class Transposes Name Expr names exprs => Selects names exprs
each :: Selects names exprs => TableSchema names -> Query exprs
values :: (Table Expr a, Foldable f) => f a -> Query a
filter :: (a -> Expr Bool) -> a -> Query a
where_ :: Expr Bool -> Query ()
present :: Query a -> Query ()
absent :: Query a -> Query ()
distinct :: EqTable a => Query a -> Query a
distinctOn :: EqTable b => (a -> b) -> Query a -> Query a
distinctOnBy :: EqTable b => (a -> b) -> Order a -> Query a -> Query a
limit :: Word -> Query a -> Query a
offset :: Word -> Query a -> Query a
union :: EqTable a => Query a -> Query a -> Query a
unionAll :: Table Expr a => Query a -> Query a -> Query a
intersect :: EqTable a => Query a -> Query a -> Query a
intersectAll :: EqTable a => Query a -> Query a -> Query a
except :: EqTable a => Query a -> Query a -> Query a
exceptAll :: EqTable a => Query a -> Query a -> Query a
exists :: Query a -> Query (Expr Bool)
with :: (a -> Query b) -> a -> Query a
withBy :: (a -> b -> Expr Bool) -> Query b -> a -> Query a
without :: (a -> Query b) -> a -> Query a
withoutBy :: (a -> b -> Expr Bool) -> Query b -> a -> Query a
data Aggregate a
class Transposes Aggregate Expr aggregates exprs => Aggregates aggregates exprs
aggregate :: Aggregates aggregates exprs => Query aggregates -> Query exprs
countRows :: Query a -> Query (Expr Int64)
groupBy :: forall exprs aggregates. (EqTable exprs, Aggregates aggregates exprs) => exprs -> aggregates
listAgg :: Aggregates aggregates exprs => exprs -> ListTable Aggregate aggregates
listAggExpr :: Sql DBType a => Expr a -> Aggregate [a]
mode :: forall a. EqTable a => Query a -> Query a
nonEmptyAgg :: Aggregates aggregates exprs => exprs -> NonEmptyTable Aggregate aggregates
nonEmptyAggExpr :: Sql DBType a => Expr a -> Aggregate (NonEmpty a)
class DBOrd a => DBMax a
max :: Sql DBMax a => Expr a -> Aggregate a
class DBOrd a => DBMin a
min :: Sql DBMin a => Expr a -> Aggregate a
class DBType a => DBSum a
sum :: Sql DBSum a => Expr a -> Aggregate a
sumWhere :: (Sql DBNum a, Sql DBSum a) => Expr Bool -> Expr a -> Aggregate a
avg :: Sql DBSum a => Expr a -> Aggregate a
class DBType a => DBString a
stringAgg :: Sql DBString a => Expr db -> Expr a -> Aggregate a
count :: Expr a -> Aggregate Int64
countStar :: Aggregate Int64
countDistinct :: Sql DBEq a => Expr a -> Aggregate Int64
countWhere :: Expr Bool -> Aggregate Int64
and :: Expr Bool -> Aggregate Bool
or :: Expr Bool -> Aggregate Bool
orderBy :: Order a -> Query a -> Query a
data Order a
asc :: DBOrd a => Order (Expr a)
desc :: DBOrd a => Order (Expr a)
nullsFirst :: Order (Expr a) -> Order (Expr (Maybe a))
nullsLast :: Order (Expr a) -> Order (Expr (Maybe a))
data Window a b
window :: Window a b -> Query a -> Query b
data Partition a
over :: Window a b -> Partition a -> Window a b
partitionBy :: forall b a. EqTable b => (a -> b) -> Partition a
orderPartitionBy :: Order a -> Partition a
cumulative :: Aggregates aggregates exprs => (a -> aggregates) -> Window a exprs
cumulative_ :: Aggregates aggregates exprs => aggregates -> Window a exprs
currentRow :: Window a a
rowNumber :: Window a (Expr Int64)
rank :: Window a (Expr Int64)
denseRank :: Window a (Expr Int64)
percentRank :: Window a (Expr Double)
cumeDist :: Window a (Expr Double)
ntile :: Expr Int32 -> Window a (Expr Int32)
lag :: Expr Int32 -> Expr a -> Window (Expr a) (Expr a)
lead :: Expr Int32 -> Expr a -> Window (Expr a) (Expr a)
firstValue :: Window (Expr a) (Expr a)
lastValue :: Window (Expr a) (Expr a)
nthValue :: Expr Int32 -> Window (Expr a) (Expr (Nullify a))
indexed :: Query a -> Query (Expr Int64, a)
rebind :: Table Expr a => String -> a -> Query a
class (ToExprs exprs a, a ~ FromExprs exprs) => Serializable exprs a | exprs -> a
class Table Expr exprs => ToExprs exprs a
type Result = Identity
select :: forall exprs a. Serializable exprs a => Query exprs -> Statement () [a]
data Insert a where
- Insert :: Selects names exprs => {..} -> Insert a
data OnConflict names
- = Abort
- | DoNothing
- | DoUpdate (Upsert names)
data Upsert names where
- Upsert :: (Selects names exprs, Projecting names index, excluded ~ exprs) => {..} -> Upsert names
insert :: Insert a -> Statement () a
unsafeDefault :: Expr a
showInsert :: Insert a -> String
data Delete a where
- Delete :: Selects names exprs => {..} -> Delete a
delete :: Delete a -> Statement () a
showDelete :: Delete a -> String
data Update a where
- Update :: Selects names exprs => {..} -> Update a
update :: Update a -> Statement () a
showUpdate :: Update a -> String
data Returning names a where
- NumberOfRowsAffected :: Returning names Int64
- Projection :: (Selects names exprs, Serializable returning a) => (exprs -> returning) -> Returning names [a]
createView :: Selects names exprs => TableSchema names -> Query exprs -> Statement () ()
createOrReplaceView :: Selects names exprs => TableSchema names -> Query exprs -> Statement () ()
nextval :: String -> Expr Int64
evaluate :: Table Expr a => a -> Query a

Database types

`DBType`

class NotNull a => DBType a where Source #

Haskell types that can be represented as expressions in a database. There should be an instance of DBType for all column types in your database schema (e.g., int, timestamptz, etc).

Rel8 comes with stock instances for most default types in PostgreSQL, so you should only need to derive instances of this class for custom database types, such as types defined in PostgreSQL extensions, or custom domain types.

Methods

typeInformation :: TypeInformation a Source #

Instances

Instances details

DBType Value Source #	Corresponds to `jsonb`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation Value Source #
DBType Int16 Source #	Corresponds to `int2`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation Int16 Source #
DBType Int32 Source #	Corresponds to `int4`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation Int32 Source #
DBType Int64 Source #	Corresponds to `int8`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation Int64 Source #
DBType ByteString Source #	Corresponds to `bytea`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation ByteString Source #
DBType ByteString Source #	Corresponds to `bytea`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation ByteString Source #
DBType Scientific Source #	Corresponds to `numeric`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation Scientific Source #
DBType Text Source #	Corresponds to `text`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation Text Source #
DBType Text Source #	Corresponds to `text`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation Text Source #
DBType Day Source #	Corresponds to `date`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation Day Source #
DBType UTCTime Source #	Corresponds to `timestamptz`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation UTCTime Source #
DBType CalendarDiffTime Source #	Corresponds to `interval`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation CalendarDiffTime Source #
DBType LocalTime Source #	Corresponds to `timestamp`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation LocalTime Source #
DBType TimeOfDay Source #	Corresponds to `time`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation TimeOfDay Source #
DBType UUID Source #	Corresponds to `uuid`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation UUID Source #
DBType Bool Source #	Corresponds to `bool`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation Bool Source #
DBType Char Source #	Corresponds to `char`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation Char Source #
DBType Double Source #	Corresponds to `float8`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation Double Source #
DBType Float Source #	Corresponds to `float4`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation Float Source #
DBType (CI Text) Source #	Corresponds to `citext`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation (CI Text) Source #
DBType (CI Text) Source #	Corresponds to `citext`
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation (CI Text) Source #
DBComposite a => DBType (Composite a) Source #
Instance details Defined in Rel8.Type.Composite Methods typeInformation :: TypeInformation (Composite a) Source #
DBEnum a => DBType (Enum a) Source #
Instance details Defined in Rel8.Type.Enum Methods typeInformation :: TypeInformation (Enum a) Source #
(FromJSON a, ToJSON a) => DBType (JSONBEncoded a) Source #
Instance details Defined in Rel8.Type.JSONBEncoded Methods typeInformation :: TypeInformation (JSONBEncoded a) Source #
(FromJSON a, ToJSON a) => DBType (JSONEncoded a) Source #
Instance details Defined in Rel8.Type.JSONEncoded Methods typeInformation :: TypeInformation (JSONEncoded a) Source #
(Read a, Show a, Typeable a) => DBType (ReadShow a) Source #
Instance details Defined in Rel8.Type.ReadShow Methods typeInformation :: TypeInformation (ReadShow a) Source #
Sql DBType a => DBType (NonEmpty a) Source #
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation (NonEmpty a) Source #
Sql DBType a => DBType [a] Source #
Instance details Defined in Rel8.Type Methods typeInformation :: TypeInformation [a] Source #

Deriving-via helpers

`JSONEncoded`

newtype JSONEncoded a Source #

A deriving-via helper type for column types that store a Haskell value using a JSON encoding described by aeson's ToJSON and FromJSON type classes.

Constructors

JSONEncoded
Fields fromJSONEncoded :: a

Instances

Instances details

(FromJSON a, ToJSON a) => DBType (JSONEncoded a) Source #
Instance details Defined in Rel8.Type.JSONEncoded Methods typeInformation :: TypeInformation (JSONEncoded a) Source #

newtype JSONBEncoded a Source #

Like JSONEncoded, but works for jsonb columns.

Constructors

JSONBEncoded
Fields fromJSONBEncoded :: a

Instances

Instances details

(FromJSON a, ToJSON a) => DBType (JSONBEncoded a) Source #
Instance details Defined in Rel8.Type.JSONBEncoded Methods typeInformation :: TypeInformation (JSONBEncoded a) Source #

`ReadShow`

newtype ReadShow a Source #

A deriving-via helper type for column types that store a Haskell value using a Haskell's Read and Show type classes.

Constructors

ReadShow
Fields fromReadShow :: a

Instances

Instances details

(Read a, Show a, Typeable a) => DBType (ReadShow a) Source #
Instance details Defined in Rel8.Type.ReadShow Methods typeInformation :: TypeInformation (ReadShow a) Source #

Generic

newtype Composite a Source #

A deriving-via helper type for column types that store a Haskell product type in a single Postgres column using a Postgres composite type.

Note that this must map to a specific extant type in your database's schema (created with CREATE TYPE). Use DBComposite to specify the name of this Postgres type and the names of the individual fields (for projecting with decompose).

Constructors

Composite a

Instances

Instances details

DBComposite a => DBType (Composite a) Source #
Instance details Defined in Rel8.Type.Composite Methods typeInformation :: TypeInformation (Composite a) Source #
(DBComposite a, EqTable (HKD a Expr)) => DBEq (Composite a) Source #
Instance details Defined in Rel8.Type.Composite
(DBComposite a, OrdTable (HKD a Expr)) => DBMax (Composite a) Source #
Instance details Defined in Rel8.Type.Composite
(DBComposite a, OrdTable (HKD a Expr)) => DBMin (Composite a) Source #
Instance details Defined in Rel8.Type.Composite
(DBComposite a, OrdTable (HKD a Expr)) => DBOrd (Composite a) Source #
Instance details Defined in Rel8.Type.Composite

class (DBType a, HKDable a) => DBComposite a where Source #

DBComposite is used to associate composite type metadata with a Haskell type.

Methods

compositeFields :: HKD a Name Source #

The names of all fields in the composite type that a maps to.

compositeTypeName :: String Source #

The name of the composite type that a maps to.

compose :: DBComposite a => HKD a Expr -> Expr a Source #

Collapse a HKD into a PostgreSQL composite type.

HKD values are represented in queries by having a column for each field in the corresponding Haskell type. compose collapses these columns into a single column expression, by combining them into a PostgreSQL composite type.

decompose :: forall a. DBComposite a => Expr a -> HKD a Expr Source #

Expand a composite type into a HKD.

decompose is the inverse of compose.

newtype Enum a Source #

A deriving-via helper type for column types that store an "enum" type (in Haskell terms, a sum type where all constructors are nullary) using a Postgres enum type.

Note that this should map to a specific type in your database's schema (explicitly created with CREATE TYPE ... AS ENUM). Use DBEnum to specify the name of this Postgres type and the names of the individual values. If left unspecified, the names of the values of the Postgres enum are assumed to match exactly exactly the names of the constructors of the Haskell type (up to and including case sensitivity).

Constructors

Enum a

Instances

Instances details

DBEnum a => DBType (Enum a) Source #
Instance details Defined in Rel8.Type.Enum Methods typeInformation :: TypeInformation (Enum a) Source #
DBEnum a => DBEq (Enum a) Source #
Instance details Defined in Rel8.Type.Enum
DBEnum a => DBMax (Enum a) Source #
Instance details Defined in Rel8.Type.Enum
DBEnum a => DBMin (Enum a) Source #
Instance details Defined in Rel8.Type.Enum
DBEnum a => DBOrd (Enum a) Source #
Instance details Defined in Rel8.Type.Enum

class (DBType a, Enumable a) => DBEnum a where Source #

DBEnum contains the necessary metadata to describe a PostgreSQL enum type.

Minimal complete definition

enumTypeName

Methods

enumValue :: a -> String Source #

Map Haskell values to the corresponding element of the enum type. The default implementation of this method will use the exact name of the Haskell constructors.

enumTypeName :: String Source #

The name of the PostgreSQL enum type that a maps to.

class (Generic a, GEnumable (Rep a)) => Enumable a Source #

Types that are sum types, where each constructor is unary (that is, has no fields).

Instances

Instances details

(Generic a, GEnumable (Rep a)) => Enumable a Source #
Instance details Defined in Rel8.Type.Enum

`TypeInformation`

data TypeInformation a Source #

TypeInformation describes how to encode and decode a Haskell type to and from database queries. The typeName is the name of the type in the database, which is used to accurately type literals.

Constructors

TypeInformation
Fields encode :: a -> PrimExpr How to encode a single Haskell value as a SQL expression. decode :: Value a How to deserialize a single result back to Haskell. typeName :: String The name of the SQL type.

mapTypeInformation :: (a -> b) -> (b -> a) -> TypeInformation a -> TypeInformation b Source #

Simultaneously map over how a type is both encoded and decoded, while retaining the name of the type. This operation is useful if you want to essentially newtype another DBType.

The mapping is required to be total. If you have a partial mapping, see parseTypeInformation.

parseTypeInformation :: (a -> Either String b) -> (b -> a) -> TypeInformation a -> TypeInformation b Source #

Apply a parser to TypeInformation.

This can be used if the data stored in the database should only be subset of a given TypeInformation. The parser is applied when deserializing rows returned - the encoder assumes that the input data is already in the appropriate form.

The `DBType` hierarchy

class DBType a => DBSemigroup a where Source #

The class of DBTypes that form a semigroup. This class is purely a Rel8 concept, and exists to mirror the Semigroup class.

Methods

(<>.) :: Expr a -> Expr a -> Expr a infixr 6 Source #

An associative operation.

Instances

Instances details

DBSemigroup ByteString Source #
Instance details Defined in Rel8.Type.Semigroup Methods (<>.) :: Expr ByteString -> Expr ByteString -> Expr ByteString Source #
DBSemigroup ByteString Source #
Instance details Defined in Rel8.Type.Semigroup Methods (<>.) :: Expr ByteString -> Expr ByteString -> Expr ByteString Source #
DBSemigroup Text Source #
Instance details Defined in Rel8.Type.Semigroup Methods (<>.) :: Expr Text -> Expr Text -> Expr Text Source #
DBSemigroup Text Source #
Instance details Defined in Rel8.Type.Semigroup Methods (<>.) :: Expr Text -> Expr Text -> Expr Text Source #
DBSemigroup CalendarDiffTime Source #
Instance details Defined in Rel8.Type.Semigroup Methods (<>.) :: Expr CalendarDiffTime -> Expr CalendarDiffTime -> Expr CalendarDiffTime Source #
DBSemigroup (CI Text) Source #
Instance details Defined in Rel8.Type.Semigroup Methods (<>.) :: Expr (CI Text) -> Expr (CI Text) -> Expr (CI Text) Source #
DBSemigroup (CI Text) Source #
Instance details Defined in Rel8.Type.Semigroup Methods (<>.) :: Expr (CI Text) -> Expr (CI Text) -> Expr (CI Text) Source #
Sql DBType a => DBSemigroup (NonEmpty a) Source #
Instance details Defined in Rel8.Type.Semigroup Methods (<>.) :: Expr (NonEmpty a) -> Expr (NonEmpty a) -> Expr (NonEmpty a) Source #
Sql DBType a => DBSemigroup [a] Source #
Instance details Defined in Rel8.Type.Semigroup Methods (<>.) :: Expr [a] -> Expr [a] -> Expr [a] Source #

class DBSemigroup a => DBMonoid a where Source #

The class of DBTypes that form a semigroup. This class is purely a Rel8 concept, and exists to mirror the Monoid class.

Methods

memptyExpr :: Expr a Source #

Instances

Instances details

DBMonoid ByteString Source #
Instance details Defined in Rel8.Type.Monoid Methods memptyExpr :: Expr ByteString Source #
DBMonoid ByteString Source #
Instance details Defined in Rel8.Type.Monoid Methods memptyExpr :: Expr ByteString Source #
DBMonoid Text Source #
Instance details Defined in Rel8.Type.Monoid Methods memptyExpr :: Expr Text Source #
DBMonoid Text Source #
Instance details Defined in Rel8.Type.Monoid Methods memptyExpr :: Expr Text Source #
DBMonoid CalendarDiffTime Source #
Instance details Defined in Rel8.Type.Monoid Methods memptyExpr :: Expr CalendarDiffTime Source #
DBMonoid (CI Text) Source #
Instance details Defined in Rel8.Type.Monoid Methods memptyExpr :: Expr (CI Text) Source #
DBMonoid (CI Text) Source #
Instance details Defined in Rel8.Type.Monoid Methods memptyExpr :: Expr (CI Text) Source #
Sql DBType a => DBMonoid [a] Source #
Instance details Defined in Rel8.Type.Monoid Methods memptyExpr :: Expr [a] Source #

class DBType a => DBNum a Source #

The class of database types that support the +, *, - operators, and the abs, negate, sign functions.

Instances

Instances details

DBNum Int16 Source #
Instance details Defined in Rel8.Type.Num
DBNum Int32 Source #
Instance details Defined in Rel8.Type.Num
DBNum Int64 Source #
Instance details Defined in Rel8.Type.Num
DBNum Scientific Source #
Instance details Defined in Rel8.Type.Num
DBNum Double Source #
Instance details Defined in Rel8.Type.Num
DBNum Float Source #
Instance details Defined in Rel8.Type.Num

class (DBNum a, DBOrd a) => DBIntegral a Source #

The class of database types that can be coerced to from integral expressions. This is a Rel8 concept, and allows us to provide fromIntegral.

Instances

Instances details

DBIntegral Int16 Source #
Instance details Defined in Rel8.Type.Num
DBIntegral Int32 Source #
Instance details Defined in Rel8.Type.Num
DBIntegral Int64 Source #
Instance details Defined in Rel8.Type.Num

class DBNum a => DBFractional a Source #

The class of database types that support the / operator.

Instances

Instances details

DBFractional Scientific Source #
Instance details Defined in Rel8.Type.Num
DBFractional Double Source #
Instance details Defined in Rel8.Type.Num
DBFractional Float Source #
Instance details Defined in Rel8.Type.Num

class DBFractional a => DBFloating a Source #

The class of database types that support the / operator.

Instances

Instances details

DBFloating Double Source #
Instance details Defined in Rel8.Type.Num
DBFloating Float Source #
Instance details Defined in Rel8.Type.Num

Tables and higher-kinded tables

class HTable (GColumns t) => Rel8able t Source #

This type class allows you to define custom Tables using higher-kinded data types. Higher-kinded data types are data types of the pattern:

data MyType f =
  MyType { field1 :: Column f T1 OR HK1 f
         , field2 :: Column f T2 OR HK2 f
         , ...
         , fieldN :: Column f Tn OR HKn f
         }

where Tn is any Haskell type, and HKn is any higher-kinded type.

That is, higher-kinded data are records where all fields in the record are all either of the type Column f T (for any T), or are themselves higher-kinded data:

Nested

data Nested f =
  Nested { nested1 :: MyType f
         , nested2 :: MyType f
         }

The Rel8able type class is used to give us a special mapping operation that lets us change the type parameter f.

Supplying Rel8able instances

This type class should be derived generically for all table types in your project. To do this, enable the DeriveAnyClass and DeriveGeneric language extensions:

{-# LANGUAGE DeriveAnyClass, DeriveGeneric #-}

data MyType f = MyType { fieldA :: Column f T }
  deriving ( GHC.Generics.Generic, Rel8able )

Instances

Instances details

ADTable t => Rel8able (ADT t) Source #
Instance details Defined in Rel8.Table.ADT Associated Types type GColumns (ADT t) :: HTable type GFromExprs (ADT t) Methods gfromColumns :: forall (context :: Context). SContext context -> GColumns (ADT t) context -> ADT t context gtoColumns :: forall (context :: Context). SContext context -> ADT t context -> GColumns (ADT t) context gfromResult :: GColumns (ADT t) Result -> GFromExprs (ADT t) gtoResult :: GFromExprs (ADT t) -> GColumns (ADT t) Result
HKDable a => Rel8able (HKD a) Source #
Instance details Defined in Rel8.Table.HKD Associated Types type GColumns (HKD a) :: HTable type GFromExprs (HKD a) Methods gfromColumns :: forall (context :: Context). SContext context -> GColumns (HKD a) context -> HKD a context gtoColumns :: forall (context :: Context). SContext context -> HKD a context -> GColumns (HKD a) context gfromResult :: GColumns (HKD a) Result -> GFromExprs (HKD a) gtoResult :: GFromExprs (HKD a) -> GColumns (HKD a) Result

type KRel8able = Rel8able Source #

The kind of Rel8able types

type family Column context a where ... Source #

This type family is used to specify columns in Rel8ables. In Column f a, f is the context of the column (which should be left polymorphic in Rel8able definitions), and a is the type of the column.

Equations

Column Result a = a
Column context a = context a

type family HADT context t where ... Source #

Equations

HADT Result t = t Result
HADT context t = ADT t context

type family HEither context = either | either -> context where ... Source #

Nest an Either value within a Rel8able. HEither f a b will produce a EitherTable a b in the Expr context, and a Either a b in the Result context.

Equations

HEither Result = Either
HEither context = EitherTable context

type family HMaybe context = maybe | maybe -> context where ... Source #

Nest a Maybe value within a Rel8able. HMaybe f a will produce a MaybeTable a in the Expr context, and a Maybe a in the Result context.

Equations

HMaybe Result = Maybe
HMaybe context = MaybeTable context

type family HList context = list | list -> context where ... Source #

Nest a list within a Rel8able. HList f a will produce a ListTable a in the Expr context, and a [a] in the Result context.

Equations

HList Result = []
HList context = ListTable context

type family HNonEmpty context = nonEmpty | nonEmpty -> context where ... Source #

Nest a NonEmpty list within a Rel8able. HNonEmpty f a will produce a NonEmptyTable a in the Expr context, and a NonEmpty a in the Result context.

Equations

HNonEmpty Result = NonEmpty
HNonEmpty context = NonEmptyTable context

type family HNull context = maybe | maybe -> context where ... Source #

Nest a Null value within a Rel8able. HNull f a will produce a NullTable a in the Expr context, and a Maybe a in the Result context.

Equations

HNull Result = Maybe
HNull context = NullTable context

type family HThese context = these | these -> context where ... Source #

Nest an These value within a Rel8able. HThese f a b will produce a TheseTable a b in the Expr context, and a These a b in the Result context.

Equations

HThese Result = These
HThese context = TheseTable context

type family Lift context a where ... Source #

Equations

Lift Result a = a
Lift context a = HKD a context

class (HTable (Columns a), context ~ Context a, a ~ Transpose context a) => Table context a | a -> context where Source #

Tables are one of the foundational elements of Rel8, and describe data types that have a finite number of columns. Each of these columns contains data under a shared context, and contexts describe how to interpret the metadata about a column to a particular Haskell type. In Rel8, we have contexts for expressions (the Expr context), aggregations (the Aggregate context), insert values (the Insert contex), among others.

In typical usage of Rel8 you don't need to derive instances of Table yourself, as anything that's an instance of Rel8able is always a Table.

Minimal complete definition

Nothing

Associated Types

type Columns a :: HTable Source #

The HTable functor that describes the schema of this table.

type Columns a = GColumns TColumns (Rep (Record a))

type Context a :: Context Source #

The common context that all columns use as an interpretation.

type Context a = GContext TContext (Rep (Record a))

type FromExprs a :: Type Source #

The FromExprs type family maps a type in the Expr context to the corresponding Haskell type.

type FromExprs a = Map TFromExprs a

type Transpose (context' :: Context) a :: Type Source #

type Transpose context a = Map (TTranspose context) a

Methods

toColumns :: a -> Columns a context Source #

default toColumns :: (Generic (Record a), GTable (TTable context) TColumns (Rep (Record a)), Columns a ~ GColumns TColumns (Rep (Record a))) => a -> Columns a context Source #

fromColumns :: Columns a context -> a Source #

default fromColumns :: (Generic (Record a), GTable (TTable context) TColumns (Rep (Record a)), Columns a ~ GColumns TColumns (Rep (Record a))) => Columns a context -> a Source #

fromResult :: Columns a Result -> FromExprs a Source #

default fromResult :: (Generic (Record (FromExprs a)), GSerialize TSerialize TColumns (Rep (Record a)) (Rep (Record (FromExprs a))), Columns a ~ GColumns TColumns (Rep (Record a))) => Columns a Result -> FromExprs a Source #

toResult :: FromExprs a -> Columns a Result Source #

default toResult :: (Generic (Record (FromExprs a)), GSerialize TSerialize TColumns (Rep (Record a)) (Rep (Record (FromExprs a))), Columns a ~ GColumns TColumns (Rep (Record a))) => FromExprs a -> Columns a Result Source #

Instances

Instances details

Sql DBType a => Table Aggregate (Aggregate a) Source #
Instance details Defined in Rel8.Aggregate Associated Types type Columns (Aggregate a) :: HTable Source # type Context (Aggregate a) :: Context Source # type FromExprs (Aggregate a) Source # type Transpose context' (Aggregate a) Source # Methods toColumns :: Aggregate a -> Columns (Aggregate a) Aggregate Source # fromColumns :: Columns (Aggregate a) Aggregate -> Aggregate a Source # fromResult :: Columns (Aggregate a) Result -> FromExprs (Aggregate a) Source # toResult :: FromExprs (Aggregate a) -> Columns (Aggregate a) Result Source #
Sql DBType a => Table Expr (Expr a) Source #
Instance details Defined in Rel8.Expr Associated Types type Columns (Expr a) :: HTable Source # type Context (Expr a) :: Context Source # type FromExprs (Expr a) Source # type Transpose context' (Expr a) Source # Methods toColumns :: Expr a -> Columns (Expr a) Expr Source # fromColumns :: Columns (Expr a) Expr -> Expr a Source # fromResult :: Columns (Expr a) Result -> FromExprs (Expr a) Source # toResult :: FromExprs (Expr a) -> Columns (Expr a) Result Source #
Sql DBType a => Table Name (Name a) Source #
Instance details Defined in Rel8.Schema.Name Associated Types type Columns (Name a) :: HTable Source # type Context (Name a) :: Context Source # type FromExprs (Name a) Source # type Transpose context' (Name a) Source # Methods toColumns :: Name a -> Columns (Name a) Name Source # fromColumns :: Columns (Name a) Name -> Name a Source # fromResult :: Columns (Name a) Result -> FromExprs (Name a) Source # toResult :: FromExprs (Name a) -> Columns (Name a) Result Source #
Sql DBType a => Table Result (Identity a) Source #
Instance details Defined in Rel8.Table Associated Types type Columns (Identity a) :: HTable Source # type Context (Identity a) :: Context Source # type FromExprs (Identity a) Source # type Transpose context' (Identity a) Source # Methods toColumns :: Identity a -> Columns (Identity a) Result Source # fromColumns :: Columns (Identity a) Result -> Identity a Source # fromResult :: Columns (Identity a) Result -> FromExprs (Identity a) Source # toResult :: FromExprs (Identity a) -> Columns (Identity a) Result Source #
(Rel8able t, Reifiable context, context ~ context') => Table context' (t context) Source #
Instance details Defined in Rel8.Table.Rel8able Associated Types type Columns (t context) :: HTable Source # type Context (t context) :: Context Source # type FromExprs (t context) Source # type Transpose context' (t context) Source # Methods toColumns :: t context -> Columns (t context) context' Source # fromColumns :: Columns (t context) context' -> t context Source # fromResult :: Columns (t context) Result -> FromExprs (t context) Source # toResult :: FromExprs (t context) -> Columns (t context) Result Source #
(Table context a, Table context b) => Table context (a, b) Source #
Instance details Defined in Rel8.Table Associated Types type Columns (a, b) :: HTable Source # type Context (a, b) :: Context Source # type FromExprs (a, b) Source # type Transpose context' (a, b) Source # Methods toColumns :: (a, b) -> Columns (a, b) context Source # fromColumns :: Columns (a, b) context -> (a, b) Source # fromResult :: Columns (a, b) Result -> FromExprs (a, b) Source # toResult :: FromExprs (a, b) -> Columns (a, b) Result Source #
(Table context a, context ~ context') => Table context' (ListTable context a) Source #
Instance details Defined in Rel8.Table.List Associated Types type Columns (ListTable context a) :: HTable Source # type Context (ListTable context a) :: Context Source # type FromExprs (ListTable context a) Source # type Transpose context' (ListTable context a) Source # Methods toColumns :: ListTable context a -> Columns (ListTable context a) context' Source # fromColumns :: Columns (ListTable context a) context' -> ListTable context a Source # fromResult :: Columns (ListTable context a) Result -> FromExprs (ListTable context a) Source # toResult :: FromExprs (ListTable context a) -> Columns (ListTable context a) Result Source #
(Table context a, Reifiable context, context ~ context') => Table context' (MaybeTable context a) Source #
Instance details Defined in Rel8.Table.Maybe Associated Types type Columns (MaybeTable context a) :: HTable Source # type Context (MaybeTable context a) :: Context Source # type FromExprs (MaybeTable context a) Source # type Transpose context' (MaybeTable context a) Source # Methods toColumns :: MaybeTable context a -> Columns (MaybeTable context a) context' Source # fromColumns :: Columns (MaybeTable context a) context' -> MaybeTable context a Source # fromResult :: Columns (MaybeTable context a) Result -> FromExprs (MaybeTable context a) Source # toResult :: FromExprs (MaybeTable context a) -> Columns (MaybeTable context a) Result Source #
(Table context a, context ~ context') => Table context' (NonEmptyTable context a) Source #
Instance details Defined in Rel8.Table.NonEmpty Associated Types type Columns (NonEmptyTable context a) :: HTable Source # type Context (NonEmptyTable context a) :: Context Source # type FromExprs (NonEmptyTable context a) Source # type Transpose context' (NonEmptyTable context a) Source # Methods toColumns :: NonEmptyTable context a -> Columns (NonEmptyTable context a) context' Source # fromColumns :: Columns (NonEmptyTable context a) context' -> NonEmptyTable context a Source # fromResult :: Columns (NonEmptyTable context a) Result -> FromExprs (NonEmptyTable context a) Source # toResult :: FromExprs (NonEmptyTable context a) -> Columns (NonEmptyTable context a) Result Source #
(Table context a, Reifiable context, context ~ context') => Table context' (NullTable context a) Source #
Instance details Defined in Rel8.Table.Null Associated Types type Columns (NullTable context a) :: HTable Source # type Context (NullTable context a) :: Context Source # type FromExprs (NullTable context a) Source # type Transpose context' (NullTable context a) Source # Methods toColumns :: NullTable context a -> Columns (NullTable context a) context' Source # fromColumns :: Columns (NullTable context a) context' -> NullTable context a Source # fromResult :: Columns (NullTable context a) Result -> FromExprs (NullTable context a) Source # toResult :: FromExprs (NullTable context a) -> Columns (NullTable context a) Result Source #
(Table context a, Table context b, Table context c) => Table context (a, b, c) Source #
Instance details Defined in Rel8.Table Associated Types type Columns (a, b, c) :: HTable Source # type Context (a, b, c) :: Context Source # type FromExprs (a, b, c) Source # type Transpose context' (a, b, c) Source # Methods toColumns :: (a, b, c) -> Columns (a, b, c) context Source # fromColumns :: Columns (a, b, c) context -> (a, b, c) Source # fromResult :: Columns (a, b, c) Result -> FromExprs (a, b, c) Source # toResult :: FromExprs (a, b, c) -> Columns (a, b, c) Result Source #
(Table context a, Table context b, Reifiable context, context ~ context') => Table context' (EitherTable context a b) Source #
Instance details Defined in Rel8.Table.Either Associated Types type Columns (EitherTable context a b) :: HTable Source # type Context (EitherTable context a b) :: Context Source # type FromExprs (EitherTable context a b) Source # type Transpose context' (EitherTable context a b) Source # Methods toColumns :: EitherTable context a b -> Columns (EitherTable context a b) context' Source # fromColumns :: Columns (EitherTable context a b) context' -> EitherTable context a b Source # fromResult :: Columns (EitherTable context a b) Result -> FromExprs (EitherTable context a b) Source # toResult :: FromExprs (EitherTable context a b) -> Columns (EitherTable context a b) Result Source #
(Table context a, Table context b, Reifiable context, context ~ context') => Table context' (TheseTable context a b) Source #
Instance details Defined in Rel8.Table.These Associated Types type Columns (TheseTable context a b) :: HTable Source # type Context (TheseTable context a b) :: Context Source # type FromExprs (TheseTable context a b) Source # type Transpose context' (TheseTable context a b) Source # Methods toColumns :: TheseTable context a b -> Columns (TheseTable context a b) context' Source # fromColumns :: Columns (TheseTable context a b) context' -> TheseTable context a b Source # fromResult :: Columns (TheseTable context a b) Result -> FromExprs (TheseTable context a b) Source # toResult :: FromExprs (TheseTable context a b) -> Columns (TheseTable context a b) Result Source #
(Table context a, Table context b, Table context c, Table context d) => Table context (a, b, c, d) Source #
Instance details Defined in Rel8.Table Associated Types type Columns (a, b, c, d) :: HTable Source # type Context (a, b, c, d) :: Context Source # type FromExprs (a, b, c, d) Source # type Transpose context' (a, b, c, d) Source # Methods toColumns :: (a, b, c, d) -> Columns (a, b, c, d) context Source # fromColumns :: Columns (a, b, c, d) context -> (a, b, c, d) Source # fromResult :: Columns (a, b, c, d) Result -> FromExprs (a, b, c, d) Source # toResult :: FromExprs (a, b, c, d) -> Columns (a, b, c, d) Result Source #
(Table context a, Table context b, Table context c, Table context d, Table context e) => Table context (a, b, c, d, e) Source #
Instance details Defined in Rel8.Table Associated Types type Columns (a, b, c, d, e) :: HTable Source # type Context (a, b, c, d, e) :: Context Source # type FromExprs (a, b, c, d, e) Source # type Transpose context' (a, b, c, d, e) Source # Methods toColumns :: (a, b, c, d, e) -> Columns (a, b, c, d, e) context Source # fromColumns :: Columns (a, b, c, d, e) context -> (a, b, c, d, e) Source # fromResult :: Columns (a, b, c, d, e) Result -> FromExprs (a, b, c, d, e) Source # toResult :: FromExprs (a, b, c, d, e) -> Columns (a, b, c, d, e) Result Source #
(Table context a, Table context b, Table context c, Table context d, Table context e, Table context f) => Table context (a, b, c, d, e, f) Source #
Instance details Defined in Rel8.Table Associated Types type Columns (a, b, c, d, e, f) :: HTable Source # type Context (a, b, c, d, e, f) :: Context Source # type FromExprs (a, b, c, d, e, f) Source # type Transpose context' (a, b, c, d, e, f) Source # Methods toColumns :: (a, b, c, d, e, f) -> Columns (a, b, c, d, e, f) context Source # fromColumns :: Columns (a, b, c, d, e, f) context -> (a, b, c, d, e, f) Source # fromResult :: Columns (a, b, c, d, e, f) Result -> FromExprs (a, b, c, d, e, f) Source # toResult :: FromExprs (a, b, c, d, e, f) -> Columns (a, b, c, d, e, f) Result Source #
(Table context a, Table context b, Table context c, Table context d, Table context e, Table context f, Table context g) => Table context (a, b, c, d, e, f, g) Source #
Instance details Defined in Rel8.Table Associated Types type Columns (a, b, c, d, e, f, g) :: HTable Source # type Context (a, b, c, d, e, f, g) :: Context Source # type FromExprs (a, b, c, d, e, f, g) Source # type Transpose context' (a, b, c, d, e, f, g) Source # Methods toColumns :: (a, b, c, d, e, f, g) -> Columns (a, b, c, d, e, f, g) context Source # fromColumns :: Columns (a, b, c, d, e, f, g) context -> (a, b, c, d, e, f, g) Source # fromResult :: Columns (a, b, c, d, e, f, g) Result -> FromExprs (a, b, c, d, e, f, g) Source # toResult :: FromExprs (a, b, c, d, e, f, g) -> Columns (a, b, c, d, e, f, g) Result Source #
Sql DBType a => Table (Field table) (Field table a) Source #
Instance details Defined in Rel8.Schema.Field Associated Types type Columns (Field table a) :: HTable Source # type Context (Field table a) :: Context Source # type FromExprs (Field table a) Source # type Transpose context' (Field table a) Source # Methods toColumns :: Field table a -> Columns (Field table a) (Field table) Source # fromColumns :: Columns (Field table a) (Field table) -> Field table a Source # fromResult :: Columns (Field table a) Result -> FromExprs (Field table a) Source # toResult :: FromExprs (Field table a) -> Columns (Field table a) Result Source #

class HTable t Source #

A HTable is a functor-indexed/higher-kinded data type that is representable (htabulate/hfield), constrainable (hdicts), and specified (hspecs).

This is an internal concept for Rel8, and you should not need to define instances yourself or specify this constraint.

class (Table from a, Table to b, Congruent a b, b ~ Transpose to a, a ~ Transpose from b) => Transposes from to a b | a -> from, b -> to, a to -> b, b from -> a Source #

Transposes from to a b means that a and b are Tables, in the from and to contexts respectively, which share the same underlying structure. In other words, b is a version of a transposed from the from context to the to context (and vice versa).

Instances

Instances details

(Table from a, Table to b, Congruent a b, b ~ Transpose to a, a ~ Transpose from b) => Transposes from to a b Source #
Instance details Defined in Rel8.Table.Transpose

class AltTable f where Source #

Like Alt in Haskell. This class is purely a Rel8 concept, and allows you to take a choice between two tables. See also AlternativeTable.

For example, using <|>: on MaybeTable allows you to combine two tables and to return the first one that is a "just" MaybeTable.

Methods

(<|>:) :: Table Expr a => f a -> f a -> f a infixl 3 Source #

An associative binary operation on Tables.

Instances

Instances details

AltTable Query Source #	`<\|>:` = `unionAll`.
Instance details Defined in Rel8.Query Methods (<\|>:) :: Table Expr a => Query a -> Query a -> Query a Source #
context ~ Expr => AltTable (ListTable context) Source #
Instance details Defined in Rel8.Table.List Methods (<\|>:) :: Table Expr a => ListTable context a -> ListTable context a -> ListTable context a Source #
context ~ Expr => AltTable (MaybeTable context) Source #
Instance details Defined in Rel8.Table.Maybe Methods (<\|>:) :: Table Expr a => MaybeTable context a -> MaybeTable context a -> MaybeTable context a Source #
context ~ Expr => AltTable (NonEmptyTable context) Source #
Instance details Defined in Rel8.Table.NonEmpty Methods (<\|>:) :: Table Expr a => NonEmptyTable context a -> NonEmptyTable context a -> NonEmptyTable context a Source #
context ~ Expr => AltTable (NullTable context) Source #
Instance details Defined in Rel8.Table.Null Methods (<\|>:) :: Table Expr a => NullTable context a -> NullTable context a -> NullTable context a Source #
EqTable k => AltTable (Tabulation k) Source #	If `Tabulation k a` is `Map k (NonEmpty a)`, then `(\|:)` is `unionWith (<>)`.
Instance details Defined in Rel8.Tabulate Methods (<\|>:) :: Table Expr a => Tabulation k a -> Tabulation k a -> Tabulation k a Source #

class AltTable f => AlternativeTable f where Source #

Like Alternative in Haskell, some Tables form a monoid on applicative functors.

Methods

emptyTable :: Table Expr a => f a Source #

The identity of <|>:.

Instances

Instances details

AlternativeTable Query Source #	`emptyTable` = `values` `[]`.
Instance details Defined in Rel8.Query Methods emptyTable :: Table Expr a => Query a Source #
context ~ Expr => AlternativeTable (ListTable context) Source #
Instance details Defined in Rel8.Table.List Methods emptyTable :: Table Expr a => ListTable context a Source #
context ~ Expr => AlternativeTable (MaybeTable context) Source #
Instance details Defined in Rel8.Table.Maybe Methods emptyTable :: Table Expr a => MaybeTable context a Source #
context ~ Expr => AlternativeTable (NullTable context) Source #
Instance details Defined in Rel8.Table.Null Methods emptyTable :: Table Expr a => NullTable context a Source #
EqTable k => AlternativeTable (Tabulation k) Source #
Instance details Defined in Rel8.Tabulate Methods emptyTable :: Table Expr a => Tabulation k a Source #

class Table Expr a => EqTable a where Source #

The class of Tables that can be compared for equality. Equality on tables is defined by equality of all columns all columns, so this class means "all columns in a Table have an instance of DBEq".

Minimal complete definition

Nothing

Methods

eqTable :: Columns a (Dict (Sql DBEq)) Source #

default eqTable :: (GTable TEqTable TColumns (Rep (Record a)), Columns a ~ GColumns TColumns (Rep (Record a))) => Columns a (Dict (Sql DBEq)) Source #

Instances

Instances details

Sql DBEq a => EqTable (Expr a) Source #
Instance details Defined in Rel8.Table.Eq Methods eqTable :: Columns (Expr a) (Dict (Sql DBEq)) Source #
(context ~ Expr, Rel8able t, HConstrainTable (Columns (t context)) (Sql DBEq)) => EqTable (t context) Source #
Instance details Defined in Rel8.Table.Rel8able Methods eqTable :: Columns (t context) (Dict (Sql DBEq)) Source #
(EqTable a, context ~ Expr) => EqTable (ListTable context a) Source #
Instance details Defined in Rel8.Table.List Methods eqTable :: Columns (ListTable context a) (Dict (Sql DBEq)) Source #
(EqTable a, context ~ Expr) => EqTable (MaybeTable context a) Source #
Instance details Defined in Rel8.Table.Maybe Methods eqTable :: Columns (MaybeTable context a) (Dict (Sql DBEq)) Source #
(EqTable a, context ~ Expr) => EqTable (NonEmptyTable context a) Source #
Instance details Defined in Rel8.Table.NonEmpty Methods eqTable :: Columns (NonEmptyTable context a) (Dict (Sql DBEq)) Source #
(EqTable a, context ~ Expr) => EqTable (NullTable context a) Source #
Instance details Defined in Rel8.Table.Null Methods eqTable :: Columns (NullTable context a) (Dict (Sql DBEq)) Source #
(EqTable a, EqTable b) => EqTable (a, b) Source #
Instance details Defined in Rel8.Table.Eq Methods eqTable :: Columns (a, b) (Dict (Sql DBEq)) Source #
(EqTable a, EqTable b, context ~ Expr) => EqTable (EitherTable context a b) Source #
Instance details Defined in Rel8.Table.Either Methods eqTable :: Columns (EitherTable context a b) (Dict (Sql DBEq)) Source #
(EqTable a, EqTable b, context ~ Expr) => EqTable (TheseTable context a b) Source #
Instance details Defined in Rel8.Table.These Methods eqTable :: Columns (TheseTable context a b) (Dict (Sql DBEq)) Source #
(EqTable a, EqTable b, EqTable c) => EqTable (a, b, c) Source #
Instance details Defined in Rel8.Table.Eq Methods eqTable :: Columns (a, b, c) (Dict (Sql DBEq)) Source #
(EqTable a, EqTable b, EqTable c, EqTable d) => EqTable (a, b, c, d) Source #
Instance details Defined in Rel8.Table.Eq Methods eqTable :: Columns (a, b, c, d) (Dict (Sql DBEq)) Source #
(EqTable a, EqTable b, EqTable c, EqTable d, EqTable e) => EqTable (a, b, c, d, e) Source #
Instance details Defined in Rel8.Table.Eq Methods eqTable :: Columns (a, b, c, d, e) (Dict (Sql DBEq)) Source #
(EqTable a, EqTable b, EqTable c, EqTable d, EqTable e, EqTable f) => EqTable (a, b, c, d, e, f) Source #
Instance details Defined in Rel8.Table.Eq Methods eqTable :: Columns (a, b, c, d, e, f) (Dict (Sql DBEq)) Source #
(EqTable a, EqTable b, EqTable c, EqTable d, EqTable e, EqTable f, EqTable g) => EqTable (a, b, c, d, e, f, g) Source #
Instance details Defined in Rel8.Table.Eq Methods eqTable :: Columns (a, b, c, d, e, f, g) (Dict (Sql DBEq)) Source #

(==:) :: forall a. EqTable a => a -> a -> Expr Bool infix 4 Source #

Compare two Tables for equality. This corresponds to comparing all columns inside each table for equality, and combining all comparisons with AND.

(/=:) :: forall a. EqTable a => a -> a -> Expr Bool infix 4 Source #

Test if two Tables are different. This corresponds to comparing all columns inside each table for inequality, and combining all comparisons with OR.

class EqTable a => OrdTable a where Source #

The class of Tables that can be ordered. Ordering on tables is defined by their lexicographic ordering of all columns, so this class means "all columns in a Table have an instance of DBOrd".

Minimal complete definition

Nothing

Methods

ordTable :: Columns a (Dict (Sql DBOrd)) Source #

default ordTable :: (GTable TOrdTable TColumns (Rep (Record a)), Columns a ~ GColumns TColumns (Rep (Record a))) => Columns a (Dict (Sql DBOrd)) Source #

Instances

Instances details

Sql DBOrd a => OrdTable (Expr a) Source #
Instance details Defined in Rel8.Table.Ord Methods ordTable :: Columns (Expr a) (Dict (Sql DBOrd)) Source #
(context ~ Expr, Rel8able t, HConstrainTable (Columns (t context)) (Sql DBEq), HConstrainTable (Columns (t context)) (Sql DBOrd)) => OrdTable (t context) Source #
Instance details Defined in Rel8.Table.Rel8able Methods ordTable :: Columns (t context) (Dict (Sql DBOrd)) Source #
(OrdTable a, context ~ Expr) => OrdTable (ListTable context a) Source #
Instance details Defined in Rel8.Table.List Methods ordTable :: Columns (ListTable context a) (Dict (Sql DBOrd)) Source #
(OrdTable a, context ~ Expr) => OrdTable (MaybeTable context a) Source #
Instance details Defined in Rel8.Table.Maybe Methods ordTable :: Columns (MaybeTable context a) (Dict (Sql DBOrd)) Source #
(OrdTable a, context ~ Expr) => OrdTable (NonEmptyTable context a) Source #
Instance details Defined in Rel8.Table.NonEmpty Methods ordTable :: Columns (NonEmptyTable context a) (Dict (Sql DBOrd)) Source #
(OrdTable a, context ~ Expr) => OrdTable (NullTable context a) Source #
Instance details Defined in Rel8.Table.Null Methods ordTable :: Columns (NullTable context a) (Dict (Sql DBOrd)) Source #
(OrdTable a, OrdTable b) => OrdTable (a, b) Source #
Instance details Defined in Rel8.Table.Ord Methods ordTable :: Columns (a, b) (Dict (Sql DBOrd)) Source #
(OrdTable a, OrdTable b, context ~ Expr) => OrdTable (EitherTable context a b) Source #
Instance details Defined in Rel8.Table.Either Methods ordTable :: Columns (EitherTable context a b) (Dict (Sql DBOrd)) Source #
(OrdTable a, OrdTable b, context ~ Expr) => OrdTable (TheseTable context a b) Source #
Instance details Defined in Rel8.Table.These Methods ordTable :: Columns (TheseTable context a b) (Dict (Sql DBOrd)) Source #
(OrdTable a, OrdTable b, OrdTable c) => OrdTable (a, b, c) Source #
Instance details Defined in Rel8.Table.Ord Methods ordTable :: Columns (a, b, c) (Dict (Sql DBOrd)) Source #
(OrdTable a, OrdTable b, OrdTable c, OrdTable d) => OrdTable (a, b, c, d) Source #
Instance details Defined in Rel8.Table.Ord Methods ordTable :: Columns (a, b, c, d) (Dict (Sql DBOrd)) Source #
(OrdTable a, OrdTable b, OrdTable c, OrdTable d, OrdTable e) => OrdTable (a, b, c, d, e) Source #
Instance details Defined in Rel8.Table.Ord Methods ordTable :: Columns (a, b, c, d, e) (Dict (Sql DBOrd)) Source #
(OrdTable a, OrdTable b, OrdTable c, OrdTable d, OrdTable e, OrdTable f) => OrdTable (a, b, c, d, e, f) Source #
Instance details Defined in Rel8.Table.Ord Methods ordTable :: Columns (a, b, c, d, e, f) (Dict (Sql DBOrd)) Source #
(OrdTable a, OrdTable b, OrdTable c, OrdTable d, OrdTable e, OrdTable f, OrdTable g) => OrdTable (a, b, c, d, e, f, g) Source #
Instance details Defined in Rel8.Table.Ord Methods ordTable :: Columns (a, b, c, d, e, f, g) (Dict (Sql DBOrd)) Source #

(<:) :: forall a. OrdTable a => a -> a -> Expr Bool infix 4 Source #

Test if one Table sorts before another. Corresponds to comparing all columns with <.

(<=:) :: forall a. OrdTable a => a -> a -> Expr Bool infix 4 Source #

Test if one Table sorts before, or is equal to, another. Corresponds to comparing all columns with <=.

(>:) :: forall a. OrdTable a => a -> a -> Expr Bool infix 4 Source #

Test if one Table sorts after another. Corresponds to comparing all columns with >.

(>=:) :: forall a. OrdTable a => a -> a -> Expr Bool infix 4 Source #

Test if one Table sorts after another. Corresponds to comparing all columns with >=.

ascTable :: forall a. OrdTable a => Order a Source #

Construct an Order for a Table by sorting all columns into ascending orders (any nullable columns will be sorted with NULLS FIRST).

descTable :: forall a. OrdTable a => Order a Source #

Construct an Order for a Table by sorting all columns into descending orders (any nullable columns will be sorted with NULLS LAST).

greatest :: OrdTable a => a -> a -> a Source #

Given two Tables, return the table that sorts after the other.

least :: OrdTable a => a -> a -> a Source #

Given two Tables, return the table that sorts before the other.

lit :: forall exprs a. Serializable exprs a => a -> exprs Source #

Use lit to turn literal Haskell values into expressions. lit is capable of lifting single Exprs to full tables.

bool :: Table Expr a => a -> a -> Expr Bool -> a Source #

An if-then-else expression on tables.

bool x y p returns x if p is False, and returns y if p is True.

case_ :: Table Expr a => [(Expr Bool, a)] -> a -> a Source #

Produce a table expression from a list of alternatives. Returns the first table where the Expr Bool expression is True. If no alternatives are true, the given default is returned.

castTable :: Table Expr a => a -> a Source #

Transform a table by adding CAST to all columns. This is most useful for finalising a SELECT or RETURNING statement, guaranteed that the output matches what is encoded in each columns TypeInformation.

`MaybeTable`

data MaybeTable context a Source #

MaybeTable t is the table t, but as the result of an outer join. If the outer join fails to match any rows, this is essentialy Nothing, and if the outer join does match rows, this is like Just. Unfortunately, SQL makes it impossible to distinguish whether or not an outer join matched any rows based generally on the row contents - if you were to join a row entirely of nulls, you can't distinguish if you matched an all null row, or if the match failed. For this reason MaybeTable contains an extra field - a "nullTag" - to track whether or not the outer join produced any rows.

Instances

Instances details

(Table context a, Reifiable context, context ~ context') => Table context' (MaybeTable context a) Source #
Instance details Defined in Rel8.Table.Maybe Associated Types type Columns (MaybeTable context a) :: HTable Source # type Context (MaybeTable context a) :: Context Source # type FromExprs (MaybeTable context a) Source # type Transpose context' (MaybeTable context a) Source # Methods toColumns :: MaybeTable context a -> Columns (MaybeTable context a) context' Source # fromColumns :: Columns (MaybeTable context a) context' -> MaybeTable context a Source # fromResult :: Columns (MaybeTable context a) Result -> FromExprs (MaybeTable context a) Source # toResult :: FromExprs (MaybeTable context a) -> Columns (MaybeTable context a) Result Source #
context ~ Expr => Applicative (MaybeTable context) Source #	Has the same behavior as the `Applicative` instance for `Maybe`. See also: `traverseMaybeTable`.
Instance details Defined in Rel8.Table.Maybe Methods pure :: a -> MaybeTable context a # (<>) :: MaybeTable context (a -> b) -> MaybeTable context a -> MaybeTable context b # liftA2 :: (a -> b -> c) -> MaybeTable context a -> MaybeTable context b -> MaybeTable context c # (>) :: MaybeTable context a -> MaybeTable context b -> MaybeTable context b # (<*) :: MaybeTable context a -> MaybeTable context b -> MaybeTable context a #
Nullifiable context => Functor (MaybeTable context) Source #
Instance details Defined in Rel8.Table.Maybe Methods fmap :: (a -> b) -> MaybeTable context a -> MaybeTable context b # (<$) :: a -> MaybeTable context b -> MaybeTable context a #
context ~ Expr => Monad (MaybeTable context) Source #	Has the same behavior as the `Monad` instance for `Maybe`.
Instance details Defined in Rel8.Table.Maybe Methods (>>=) :: MaybeTable context a -> (a -> MaybeTable context b) -> MaybeTable context b # (>>) :: MaybeTable context a -> MaybeTable context b -> MaybeTable context b # return :: a -> MaybeTable context a #
context ~ Expr => AltTable (MaybeTable context) Source #
Instance details Defined in Rel8.Table.Maybe Methods (<\|>:) :: Table Expr a => MaybeTable context a -> MaybeTable context a -> MaybeTable context a Source #
context ~ Expr => AlternativeTable (MaybeTable context) Source #
Instance details Defined in Rel8.Table.Maybe Methods emptyTable :: Table Expr a => MaybeTable context a Source #
Projectable (MaybeTable context) Source #
Instance details Defined in Rel8.Table.Maybe Methods project :: Projecting a b => Projection a b -> MaybeTable context a -> MaybeTable context b Source #
context ~ Expr => Apply (MaybeTable context) Source #
Instance details Defined in Rel8.Table.Maybe Methods (<.>) :: MaybeTable context (a -> b) -> MaybeTable context a -> MaybeTable context b # (.>) :: MaybeTable context a -> MaybeTable context b -> MaybeTable context b # (<.) :: MaybeTable context a -> MaybeTable context b -> MaybeTable context a # liftF2 :: (a -> b -> c) -> MaybeTable context a -> MaybeTable context b -> MaybeTable context c #
context ~ Expr => Bind (MaybeTable context) Source #
Instance details Defined in Rel8.Table.Maybe Methods (>>-) :: MaybeTable context a -> (a -> MaybeTable context b) -> MaybeTable context b # join :: MaybeTable context (MaybeTable context a) -> MaybeTable context a #
(context ~ Expr, Table Expr a, Semigroup a) => Monoid (MaybeTable context a) Source #
Instance details Defined in Rel8.Table.Maybe Methods mempty :: MaybeTable context a # mappend :: MaybeTable context a -> MaybeTable context a -> MaybeTable context a # mconcat :: [MaybeTable context a] -> MaybeTable context a #
(context ~ Expr, Table Expr a, Semigroup a) => Semigroup (MaybeTable context a) Source #
Instance details Defined in Rel8.Table.Maybe Methods (<>) :: MaybeTable context a -> MaybeTable context a -> MaybeTable context a # sconcat :: NonEmpty (MaybeTable context a) -> MaybeTable context a # stimes :: Integral b => b -> MaybeTable context a -> MaybeTable context a #
(EqTable a, context ~ Expr) => EqTable (MaybeTable context a) Source #
Instance details Defined in Rel8.Table.Maybe Methods eqTable :: Columns (MaybeTable context a) (Dict (Sql DBEq)) Source #
(OrdTable a, context ~ Expr) => OrdTable (MaybeTable context a) Source #
Instance details Defined in Rel8.Table.Maybe Methods ordTable :: Columns (MaybeTable context a) (Dict (Sql DBOrd)) Source #
(ToExprs exprs a, context ~ Expr) => ToExprs (MaybeTable context exprs) (Maybe a) Source #
Instance details Defined in Rel8.Table.Maybe
type Transpose to (MaybeTable context a) Source #
Instance details Defined in Rel8.Table.Maybe type Transpose to (MaybeTable context a) = MaybeTable to (Transpose to a)
type Columns (MaybeTable context a) Source #
Instance details Defined in Rel8.Table.Maybe type Columns (MaybeTable context a)
type Context (MaybeTable context a) Source #
Instance details Defined in Rel8.Table.Maybe type Context (MaybeTable context a) = Context a
type FromExprs (MaybeTable context a) Source #
Instance details Defined in Rel8.Table.Maybe type FromExprs (MaybeTable context a) = Maybe (FromExprs a)

maybeTable :: Table Expr b => b -> (a -> b) -> MaybeTable Expr a -> b Source #

Perform case analysis on a MaybeTable. Like maybe.

($?) :: forall a b. Sql DBType b => (a -> Expr b) -> MaybeTable Expr a -> Expr (Nullify b) infixl 4 Source #

Project a single expression out of a MaybeTable. You can think of this operator like the $ operator, but it also has the ability to return null.

nothingTable :: Table Expr a => MaybeTable Expr a Source #

The null table. Like Nothing.

justTable :: a -> MaybeTable Expr a Source #

Lift any table into MaybeTable. Like Just. Note you can also use pure.

isNothingTable :: MaybeTable Expr a -> Expr Bool Source #

Check if a MaybeTable is absent of any row. Like isNothing.

isJustTable :: MaybeTable Expr a -> Expr Bool Source #

Check if a MaybeTable contains a row. Like isJust.

fromMaybeTable :: Table Expr a => a -> MaybeTable Expr a -> a Source #

fromMaybe for MaybeTables.

optional :: Query a -> Query (MaybeTable Expr a) Source #

Convert a query that might return zero rows to a query that always returns at least one row.

To speak in more concrete terms, optional is most useful to write LEFT JOINs.

catMaybeTable :: MaybeTable Expr a -> Query a Source #

Filter out MaybeTables, returning only the tables that are not-null.

This operation can be used to "undo" the effect of optional, which operationally is like turning a LEFT JOIN back into a full JOIN. You can think of this as analogous to catMaybes.

traverseMaybeTable :: (a -> Query b) -> MaybeTable Expr a -> Query (MaybeTable Expr b) Source #

Extend an optional query with another query. This is useful if you want to step through multiple LEFT JOINs.

Note that traverseMaybeTable takes a a -> Query b function, which means you also have the ability to "expand" one row into multiple rows. If the a -> Query b function returns no rows, then the resulting query will also have no rows. However, regardless of the given a -> Query b function, if the input is nothingTable, you will always get exactly one nothingTable back.

aggregateMaybeTable :: (exprs -> aggregates) -> MaybeTable Expr exprs -> MaybeTable Aggregate aggregates Source #

Lift an aggregating function to operate on a MaybeTable. nothingTables and justTables are grouped separately.

nameMaybeTable Source #

Arguments

:: Name (Maybe MaybeTag)	The name of the column to track whether a row is a `justTable` or `nothingTable`.
-> a	Names of the columns in `a`.
-> MaybeTable Name a

Construct a MaybeTable in the Name context. This can be useful if you have a MaybeTable that you are storing in a table and need to construct a TableSchema.

`EitherTable`

data EitherTable context a b Source #

An EitherTable a b is a Rel8 table that contains either the table a or the table b. You can construct an EitherTable using leftTable and rightTable, and eliminate/pattern match using eitherTable.

An EitherTable is operationally the same as Haskell's Either type, but adapted to work with Rel8.

Instances

Instances details

(Table context a, Table context b, Reifiable context, context ~ context') => Table context' (EitherTable context a b) Source #
Instance details Defined in Rel8.Table.Either Associated Types type Columns (EitherTable context a b) :: HTable Source # type Context (EitherTable context a b) :: Context Source # type FromExprs (EitherTable context a b) Source # type Transpose context' (EitherTable context a b) Source # Methods toColumns :: EitherTable context a b -> Columns (EitherTable context a b) context' Source # fromColumns :: Columns (EitherTable context a b) context' -> EitherTable context a b Source # fromResult :: Columns (EitherTable context a b) Result -> FromExprs (EitherTable context a b) Source # toResult :: FromExprs (EitherTable context a b) -> Columns (EitherTable context a b) Result Source #
Nullifiable context => Bifunctor (EitherTable context) Source #
Instance details Defined in Rel8.Table.Either Methods bimap :: (a -> b) -> (c -> d) -> EitherTable context a c -> EitherTable context b d # first :: (a -> b) -> EitherTable context a c -> EitherTable context b c # second :: (b -> c) -> EitherTable context a b -> EitherTable context a c #
Biprojectable (EitherTable context) Source #
Instance details Defined in Rel8.Table.Either Methods biproject :: (Projecting a b, Projecting c d) => Projection a b -> Projection c d -> EitherTable context a c -> EitherTable context b d Source #
(context ~ Expr, Table Expr a) => Applicative (EitherTable context a) Source #
Instance details Defined in Rel8.Table.Either Methods pure :: a0 -> EitherTable context a a0 # (<>) :: EitherTable context a (a0 -> b) -> EitherTable context a a0 -> EitherTable context a b # liftA2 :: (a0 -> b -> c) -> EitherTable context a a0 -> EitherTable context a b -> EitherTable context a c # (>) :: EitherTable context a a0 -> EitherTable context a b -> EitherTable context a b # (<*) :: EitherTable context a a0 -> EitherTable context a b -> EitherTable context a a0 #
Nullifiable context => Functor (EitherTable context a) Source #
Instance details Defined in Rel8.Table.Either Methods fmap :: (a0 -> b) -> EitherTable context a a0 -> EitherTable context a b # (<$) :: a0 -> EitherTable context a b -> EitherTable context a a0 #
(context ~ Expr, Table Expr a) => Monad (EitherTable context a) Source #
Instance details Defined in Rel8.Table.Either Methods (>>=) :: EitherTable context a a0 -> (a0 -> EitherTable context a b) -> EitherTable context a b # (>>) :: EitherTable context a a0 -> EitherTable context a b -> EitherTable context a b # return :: a0 -> EitherTable context a a0 #
Projectable (EitherTable context a) Source #
Instance details Defined in Rel8.Table.Either Methods project :: Projecting a0 b => Projection a0 b -> EitherTable context a a0 -> EitherTable context a b Source #
(context ~ Expr, Table Expr a) => Apply (EitherTable context a) Source #
Instance details Defined in Rel8.Table.Either Methods (<.>) :: EitherTable context a (a0 -> b) -> EitherTable context a a0 -> EitherTable context a b # (.>) :: EitherTable context a a0 -> EitherTable context a b -> EitherTable context a b # (<.) :: EitherTable context a a0 -> EitherTable context a b -> EitherTable context a a0 # liftF2 :: (a0 -> b -> c) -> EitherTable context a a0 -> EitherTable context a b -> EitherTable context a c #
(context ~ Expr, Table Expr a) => Bind (EitherTable context a) Source #
Instance details Defined in Rel8.Table.Either Methods (>>-) :: EitherTable context a a0 -> (a0 -> EitherTable context a b) -> EitherTable context a b # join :: EitherTable context a (EitherTable context a a0) -> EitherTable context a a0 #
(context ~ Expr, Table Expr a, Table Expr b) => Semigroup (EitherTable context a b) Source #
Instance details Defined in Rel8.Table.Either Methods (<>) :: EitherTable context a b -> EitherTable context a b -> EitherTable context a b # sconcat :: NonEmpty (EitherTable context a b) -> EitherTable context a b # stimes :: Integral b0 => b0 -> EitherTable context a b -> EitherTable context a b #
(EqTable a, EqTable b, context ~ Expr) => EqTable (EitherTable context a b) Source #
Instance details Defined in Rel8.Table.Either Methods eqTable :: Columns (EitherTable context a b) (Dict (Sql DBEq)) Source #
(OrdTable a, OrdTable b, context ~ Expr) => OrdTable (EitherTable context a b) Source #
Instance details Defined in Rel8.Table.Either Methods ordTable :: Columns (EitherTable context a b) (Dict (Sql DBOrd)) Source #
type Transpose to (EitherTable context a b) Source #
Instance details Defined in Rel8.Table.Either type Transpose to (EitherTable context a b) = EitherTable to (Transpose to a) (Transpose to b)
type Columns (EitherTable context a b) Source #
Instance details Defined in Rel8.Table.Either type Columns (EitherTable context a b)
type Context (EitherTable context a b) Source #
Instance details Defined in Rel8.Table.Either type Context (EitherTable context a b) = Context a
type FromExprs (EitherTable context a b) Source #
Instance details Defined in Rel8.Table.Either type FromExprs (EitherTable context a b) = Either (FromExprs a) (FromExprs b)

eitherTable :: Table Expr c => (a -> c) -> (b -> c) -> EitherTable Expr a b -> c Source #

Pattern match/eliminate an EitherTable, by providing mappings from a leftTable and rightTable.

leftTable :: Table Expr b => a -> EitherTable Expr a b Source #

Construct a left EitherTable. Like Left.

rightTable :: Table Expr a => b -> EitherTable Expr a b Source #

Construct a right EitherTable. Like Right.

isLeftTable :: EitherTable Expr a b -> Expr Bool Source #

Test if an EitherTable is a leftTable.

isRightTable :: EitherTable Expr a b -> Expr Bool Source #

Test if an EitherTable is a rightTable.

keepLeftTable :: EitherTable Expr a b -> Query a Source #

Filter EitherTables, keeping only leftTables.

keepRightTable :: EitherTable Expr a b -> Query b Source #

Filter EitherTables, keeping only rightTables.

bitraverseEitherTable :: (a -> Query c) -> (b -> Query d) -> EitherTable Expr a b -> Query (EitherTable Expr c d) Source #

bitraverseEitherTable f g x will pass all leftTables through f and all rightTables through g. The results are then lifted back into leftTable and rightTable, respectively. This is similar to bitraverse for Either.

For example,

>>> :{
select do
  x <- values (map lit [ Left True, Right (42 :: Int32) ])
  bitraverseEitherTable (\y -> values [y, not_ y]) (\y -> pure (y * 100)) x
:}
[ Left True
, Left False
, Right 4200
]

aggregateEitherTable :: (exprs -> aggregates) -> (exprs' -> aggregates') -> EitherTable Expr exprs exprs' -> EitherTable Aggregate aggregates aggregates' Source #

Lift a pair of aggregating functions to operate on an EitherTable. leftTables and rightTables are grouped separately.

nameEitherTable Source #

Arguments

:: Name EitherTag	The name of the column to track whether a row is a `leftTable` or `rightTable`.
-> a	Names of the columns in the `a` table.
-> b	Names of the columns in the `b` table.
-> EitherTable Name a b

Construct a EitherTable in the Name context. This can be useful if you have a EitherTable that you are storing in a table and need to construct a TableSchema.

`TheseTable`

data TheseTable context a b Source #

TheseTable a b is a Rel8 table that contains either the table a, the table b, or both tables a and b. You can construct TheseTables using thisTable, thatTable and thoseTable. TheseTables can be eliminated/pattern matched using theseTable.

TheseTable is operationally the same as Haskell's These type, but adapted to work with Rel8.

Instances

Instances details

(Table context a, Table context b, Reifiable context, context ~ context') => Table context' (TheseTable context a b) Source #
Instance details Defined in Rel8.Table.These Associated Types type Columns (TheseTable context a b) :: HTable Source # type Context (TheseTable context a b) :: Context Source # type FromExprs (TheseTable context a b) Source # type Transpose context' (TheseTable context a b) Source # Methods toColumns :: TheseTable context a b -> Columns (TheseTable context a b) context' Source # fromColumns :: Columns (TheseTable context a b) context' -> TheseTable context a b Source # fromResult :: Columns (TheseTable context a b) Result -> FromExprs (TheseTable context a b) Source # toResult :: FromExprs (TheseTable context a b) -> Columns (TheseTable context a b) Result Source #
Nullifiable context => Bifunctor (TheseTable context) Source #
Instance details Defined in Rel8.Table.These Methods bimap :: (a -> b) -> (c -> d) -> TheseTable context a c -> TheseTable context b d # first :: (a -> b) -> TheseTable context a c -> TheseTable context b c # second :: (b -> c) -> TheseTable context a b -> TheseTable context a c #
Biprojectable (TheseTable context) Source #
Instance details Defined in Rel8.Table.These Methods biproject :: (Projecting a b, Projecting c d) => Projection a b -> Projection c d -> TheseTable context a c -> TheseTable context b d Source #
(context ~ Expr, Table Expr a, Semigroup a) => Applicative (TheseTable context a) Source #
Instance details Defined in Rel8.Table.These Methods pure :: a0 -> TheseTable context a a0 # (<>) :: TheseTable context a (a0 -> b) -> TheseTable context a a0 -> TheseTable context a b # liftA2 :: (a0 -> b -> c) -> TheseTable context a a0 -> TheseTable context a b -> TheseTable context a c # (>) :: TheseTable context a a0 -> TheseTable context a b -> TheseTable context a b # (<*) :: TheseTable context a a0 -> TheseTable context a b -> TheseTable context a a0 #
Nullifiable context => Functor (TheseTable context a) Source #
Instance details Defined in Rel8.Table.These Methods fmap :: (a0 -> b) -> TheseTable context a a0 -> TheseTable context a b # (<$) :: a0 -> TheseTable context a b -> TheseTable context a a0 #
(context ~ Expr, Table Expr a, Semigroup a) => Monad (TheseTable context a) Source #
Instance details Defined in Rel8.Table.These Methods (>>=) :: TheseTable context a a0 -> (a0 -> TheseTable context a b) -> TheseTable context a b # (>>) :: TheseTable context a a0 -> TheseTable context a b -> TheseTable context a b # return :: a0 -> TheseTable context a a0 #
Projectable (TheseTable context a) Source #
Instance details Defined in Rel8.Table.These Methods project :: Projecting a0 b => Projection a0 b -> TheseTable context a a0 -> TheseTable context a b Source #
(context ~ Expr, Table Expr a, Semigroup a) => Apply (TheseTable context a) Source #
Instance details Defined in Rel8.Table.These Methods (<.>) :: TheseTable context a (a0 -> b) -> TheseTable context a a0 -> TheseTable context a b # (.>) :: TheseTable context a a0 -> TheseTable context a b -> TheseTable context a b # (<.) :: TheseTable context a a0 -> TheseTable context a b -> TheseTable context a a0 # liftF2 :: (a0 -> b -> c) -> TheseTable context a a0 -> TheseTable context a b -> TheseTable context a c #
(context ~ Expr, Table Expr a, Semigroup a) => Bind (TheseTable context a) Source #
Instance details Defined in Rel8.Table.These Methods (>>-) :: TheseTable context a a0 -> (a0 -> TheseTable context a b) -> TheseTable context a b # join :: TheseTable context a (TheseTable context a a0) -> TheseTable context a a0 #
(context ~ Expr, Table Expr a, Table Expr b, Semigroup a, Semigroup b) => Semigroup (TheseTable context a b) Source #
Instance details Defined in Rel8.Table.These Methods (<>) :: TheseTable context a b -> TheseTable context a b -> TheseTable context a b # sconcat :: NonEmpty (TheseTable context a b) -> TheseTable context a b # stimes :: Integral b0 => b0 -> TheseTable context a b -> TheseTable context a b #
(EqTable a, EqTable b, context ~ Expr) => EqTable (TheseTable context a b) Source #
Instance details Defined in Rel8.Table.These Methods eqTable :: Columns (TheseTable context a b) (Dict (Sql DBEq)) Source #
(OrdTable a, OrdTable b, context ~ Expr) => OrdTable (TheseTable context a b) Source #
Instance details Defined in Rel8.Table.These Methods ordTable :: Columns (TheseTable context a b) (Dict (Sql DBOrd)) Source #
type Transpose to (TheseTable context a b) Source #
Instance details Defined in Rel8.Table.These type Transpose to (TheseTable context a b) = TheseTable to (Transpose to a) (Transpose to b)
type Columns (TheseTable context a b) Source #
Instance details Defined in Rel8.Table.These type Columns (TheseTable context a b)
type Context (TheseTable context a b) Source #
Instance details Defined in Rel8.Table.These type Context (TheseTable context a b) = Context a
type FromExprs (TheseTable context a b) Source #
Instance details Defined in Rel8.Table.These type FromExprs (TheseTable context a b) = These (FromExprs a) (FromExprs b)

theseTable :: Table Expr c => (a -> c) -> (b -> c) -> (a -> b -> c) -> TheseTable Expr a b -> c Source #

Pattern match on a TheseTable. Corresponds to these.

thisTable :: Table Expr b => a -> TheseTable Expr a b Source #

Construct a TheseTable. Corresponds to This.

thatTable :: Table Expr a => b -> TheseTable Expr a b Source #

Construct a TheseTable. Corresponds to That.

thoseTable :: a -> b -> TheseTable Expr a b Source #

Construct a TheseTable. Corresponds to These.

isThisTable :: TheseTable Expr a b -> Expr Bool Source #

Test if a TheseTable was constructed with thisTable.

Corresponds to isThis.

isThatTable :: TheseTable Expr a b -> Expr Bool Source #

Test if a TheseTable was constructed with thatTable.

Corresponds to isThat.

isThoseTable :: TheseTable Expr a b -> Expr Bool Source #

Test if a TheseTable was constructed with thoseTable.

Corresponds to isThese.

hasHereTable :: TheseTable Expr a b -> Expr Bool Source #

Test if the a side of TheseTable a b is present.

Corresponds to hasHere.

hasThereTable :: TheseTable Expr a b -> Expr Bool Source #

Test if the b table of TheseTable a b is present.

Corresponds to hasThere.

justHereTable :: TheseTable context a b -> MaybeTable context a Source #

Attempt to project out the a table of a TheseTable a b.

Corresponds to justHere.

justThereTable :: TheseTable context a b -> MaybeTable context b Source #

Attempt to project out the b table of a TheseTable a b.

Corresponds to justThere.

alignMaybeTable :: MaybeTable Expr a -> MaybeTable Expr b -> MaybeTable Expr (TheseTable Expr a b) Source #

Construct a TheseTable from two MaybeTables.

alignBy :: (a -> b -> Expr Bool) -> Query a -> Query b -> Query (TheseTable Expr a b) Source #

Corresponds to a FULL OUTER JOIN between two queries.

keepHereTable :: TheseTable Expr a b -> Query (a, MaybeTable Expr b) Source #

loseHereTable :: TheseTable Expr a b -> Query b Source #

keepThereTable :: TheseTable Expr a b -> Query (MaybeTable Expr a, b) Source #

loseThereTable :: TheseTable Expr a b -> Query a Source #

keepThisTable :: TheseTable Expr a b -> Query a Source #

loseThisTable :: TheseTable Expr a b -> Query (MaybeTable Expr a, b) Source #

keepThatTable :: TheseTable Expr a b -> Query b Source #

loseThatTable :: TheseTable Expr a b -> Query (a, MaybeTable Expr b) Source #

keepThoseTable :: TheseTable Expr a b -> Query (a, b) Source #

loseThoseTable :: TheseTable Expr a b -> Query (EitherTable Expr a b) Source #

bitraverseTheseTable :: (a -> Query c) -> (b -> Query d) -> TheseTable Expr a b -> Query (TheseTable Expr c d) Source #

aggregateTheseTable :: (exprs -> aggregates) -> (exprs' -> aggregates') -> TheseTable Expr exprs exprs' -> TheseTable Aggregate aggregates aggregates' Source #

Lift a pair of aggregating functions to operate on an TheseTable. thisTables, thatTables and thoseTables are grouped separately.

nameTheseTable Source #

Arguments

:: Name (Maybe MaybeTag)	The name of the column to track the presence of the `a` table.
-> Name (Maybe MaybeTag)	The name of the column to track the presence of the `b` table.
-> a	Names of the columns in the `a` table.
-> b	Names of the columns in the `b` table.
-> TheseTable Name a b

Construct a TheseTable in the Name context. This can be useful if you have a TheseTable that you are storing in a table and need to construct a TableSchema.

`ListTable`

data ListTable context a Source #

A ListTable value contains zero or more instances of a. You construct ListTables with many or listAgg.

Instances

Instances details

(Table context a, context ~ context') => Table context' (ListTable context a) Source #
Instance details Defined in Rel8.Table.List Associated Types type Columns (ListTable context a) :: HTable Source # type Context (ListTable context a) :: Context Source # type FromExprs (ListTable context a) Source # type Transpose context' (ListTable context a) Source # Methods toColumns :: ListTable context a -> Columns (ListTable context a) context' Source # fromColumns :: Columns (ListTable context a) context' -> ListTable context a Source # fromResult :: Columns (ListTable context a) Result -> FromExprs (ListTable context a) Source # toResult :: FromExprs (ListTable context a) -> Columns (ListTable context a) Result Source #
context ~ Expr => AltTable (ListTable context) Source #
Instance details Defined in Rel8.Table.List Methods (<\|>:) :: Table Expr a => ListTable context a -> ListTable context a -> ListTable context a Source #
context ~ Expr => AlternativeTable (ListTable context) Source #
Instance details Defined in Rel8.Table.List Methods emptyTable :: Table Expr a => ListTable context a Source #
Projectable (ListTable context) Source #
Instance details Defined in Rel8.Table.List Methods project :: Projecting a b => Projection a b -> ListTable context a -> ListTable context b Source #
(context ~ Expr, Table Expr a) => Monoid (ListTable context a) Source #
Instance details Defined in Rel8.Table.List Methods mempty :: ListTable context a # mappend :: ListTable context a -> ListTable context a -> ListTable context a # mconcat :: [ListTable context a] -> ListTable context a #
(context ~ Expr, Table Expr a) => Semigroup (ListTable context a) Source #
Instance details Defined in Rel8.Table.List Methods (<>) :: ListTable context a -> ListTable context a -> ListTable context a # sconcat :: NonEmpty (ListTable context a) -> ListTable context a # stimes :: Integral b => b -> ListTable context a -> ListTable context a #
(EqTable a, context ~ Expr) => EqTable (ListTable context a) Source #
Instance details Defined in Rel8.Table.List Methods eqTable :: Columns (ListTable context a) (Dict (Sql DBEq)) Source #
(OrdTable a, context ~ Expr) => OrdTable (ListTable context a) Source #
Instance details Defined in Rel8.Table.List Methods ordTable :: Columns (ListTable context a) (Dict (Sql DBOrd)) Source #
(ToExprs exprs a, context ~ Expr) => ToExprs (ListTable context exprs) [a] Source #
Instance details Defined in Rel8.Table.List
type Transpose to (ListTable context a) Source #
Instance details Defined in Rel8.Table.List type Transpose to (ListTable context a) = ListTable to (Transpose to a)
type Columns (ListTable context a) Source #
Instance details Defined in Rel8.Table.List type Columns (ListTable context a)
type Context (ListTable context a) Source #
Instance details Defined in Rel8.Table.List type Context (ListTable context a) = Context a
type FromExprs (ListTable context a) Source #
Instance details Defined in Rel8.Table.List type FromExprs (ListTable context a) = [FromExprs a]

listTable :: Table Expr a => [a] -> ListTable Expr a Source #

Construct a ListTable from a list of expressions.

($*) :: Projecting a (Expr b) => Projection a (Expr b) -> ListTable Expr a -> Expr [b] infixl 4 Source #

Project a single expression out of a ListTable.

nameListTable Source #

Arguments

:: Table Name a
=> a	The names of the columns of elements of the list.
-> ListTable Name a

Construct a ListTable in the Name context. This can be useful if you have a ListTable that you are storing in a table and need to construct a TableSchema.

many :: Table Expr a => Query a -> Query (ListTable Expr a) Source #

Aggregate a Query into a ListTable. If the supplied query returns 0 rows, this function will produce a Query that returns one row containing the empty ListTable. If the supplied Query does return rows, many will return exactly one row, with a ListTable collecting all returned rows.

many is analogous to many from Control.Applicative.

manyExpr :: Sql DBType a => Query (Expr a) -> Query (Expr [a]) Source #

A version of many specialised to single expressions.

catListTable :: Table Expr a => ListTable Expr a -> Query a Source #

Expand a ListTable into a Query, where each row in the query is an element of the given ListTable.

catListTable is an inverse to many.

catList :: Sql DBType a => Expr [a] -> Query (Expr a) Source #

Expand an expression that contains a list into a Query, where each row in the query is an element of the given list.

catList is an inverse to manyExpr.

`NonEmptyTable`

data NonEmptyTable context a Source #

A NonEmptyTable value contains one or more instances of a. You construct NonEmptyTables with some or nonEmptyAgg.

Instances

Instances details

(Table context a, context ~ context') => Table context' (NonEmptyTable context a) Source #
Instance details Defined in Rel8.Table.NonEmpty Associated Types type Columns (NonEmptyTable context a) :: HTable Source # type Context (NonEmptyTable context a) :: Context Source # type FromExprs (NonEmptyTable context a) Source # type Transpose context' (NonEmptyTable context a) Source # Methods toColumns :: NonEmptyTable context a -> Columns (NonEmptyTable context a) context' Source # fromColumns :: Columns (NonEmptyTable context a) context' -> NonEmptyTable context a Source # fromResult :: Columns (NonEmptyTable context a) Result -> FromExprs (NonEmptyTable context a) Source # toResult :: FromExprs (NonEmptyTable context a) -> Columns (NonEmptyTable context a) Result Source #
context ~ Expr => AltTable (NonEmptyTable context) Source #
Instance details Defined in Rel8.Table.NonEmpty Methods (<\|>:) :: Table Expr a => NonEmptyTable context a -> NonEmptyTable context a -> NonEmptyTable context a Source #
Projectable (NonEmptyTable context) Source #
Instance details Defined in Rel8.Table.NonEmpty Methods project :: Projecting a b => Projection a b -> NonEmptyTable context a -> NonEmptyTable context b Source #
(Table Expr a, context ~ Expr) => Semigroup (NonEmptyTable context a) Source #
Instance details Defined in Rel8.Table.NonEmpty Methods (<>) :: NonEmptyTable context a -> NonEmptyTable context a -> NonEmptyTable context a # sconcat :: NonEmpty (NonEmptyTable context a) -> NonEmptyTable context a # stimes :: Integral b => b -> NonEmptyTable context a -> NonEmptyTable context a #
(EqTable a, context ~ Expr) => EqTable (NonEmptyTable context a) Source #
Instance details Defined in Rel8.Table.NonEmpty Methods eqTable :: Columns (NonEmptyTable context a) (Dict (Sql DBEq)) Source #
(OrdTable a, context ~ Expr) => OrdTable (NonEmptyTable context a) Source #
Instance details Defined in Rel8.Table.NonEmpty Methods ordTable :: Columns (NonEmptyTable context a) (Dict (Sql DBOrd)) Source #
(ToExprs exprs a, context ~ Expr) => ToExprs (NonEmptyTable context exprs) (NonEmpty a) Source #
Instance details Defined in Rel8.Table.NonEmpty
type Transpose to (NonEmptyTable context a) Source #
Instance details Defined in Rel8.Table.NonEmpty type Transpose to (NonEmptyTable context a) = NonEmptyTable to (Transpose to a)
type Columns (NonEmptyTable context a) Source #
Instance details Defined in Rel8.Table.NonEmpty type Columns (NonEmptyTable context a)
type Context (NonEmptyTable context a) Source #
Instance details Defined in Rel8.Table.NonEmpty type Context (NonEmptyTable context a) = Context a
type FromExprs (NonEmptyTable context a) Source #
Instance details Defined in Rel8.Table.NonEmpty type FromExprs (NonEmptyTable context a) = NonEmpty (FromExprs a)

nonEmptyTable :: Table Expr a => NonEmpty a -> NonEmptyTable Expr a Source #

Construct a NonEmptyTable from a non-empty list of expressions.

($+) :: Projecting a (Expr b) => Projection a (Expr b) -> NonEmptyTable Expr a -> Expr (NonEmpty b) infixl 4 Source #

Project a single expression out of a NonEmptyTable.

nameNonEmptyTable Source #

Arguments

:: Table Name a
=> a	The names of the columns of elements of the list.
-> NonEmptyTable Name a

Construct a NonEmptyTable in the Name context. This can be useful if you have a NonEmptyTable that you are storing in a table and need to construct a TableSchema.

some :: Table Expr a => Query a -> Query (NonEmptyTable Expr a) Source #

Aggregate a Query into a NonEmptyTable. If the supplied query returns 0 rows, this function will produce a Query that is empty - that is, will produce zero NonEmptyTables. If the supplied Query does return rows, some will return exactly one row, with a NonEmptyTable collecting all returned rows.

some is analogous to some from Control.Applicative.

someExpr :: Sql DBType a => Query (Expr a) -> Query (Expr (NonEmpty a)) Source #

A version of many specialised to single expressions.

catNonEmptyTable :: Table Expr a => NonEmptyTable Expr a -> Query a Source #

Expand a NonEmptyTable into a Query, where each row in the query is an element of the given NonEmptyTable.

catNonEmptyTable is an inverse to some.

catNonEmpty :: Sql DBType a => Expr (NonEmpty a) -> Query (Expr a) Source #

Expand an expression that contains a non-empty list into a Query, where each row in the query is an element of the given list.

catNonEmpty is an inverse to someExpr.

`NullTable`

data NullTable context a Source #

NullTable t is the table t, but where all the columns in t have the possibility of being null. This is very similar to MaybeTable, except that it does not use an extra tag field, so it cannot distinguish between Nothing and Just Nothing if nested. In other words, if all of the columns of the t passed to NullTable are already nullable, then NullTable has no effect.

Instances

Instances details

(Table context a, Reifiable context, context ~ context') => Table context' (NullTable context a) Source #
Instance details Defined in Rel8.Table.Null Associated Types type Columns (NullTable context a) :: HTable Source # type Context (NullTable context a) :: Context Source # type FromExprs (NullTable context a) Source # type Transpose context' (NullTable context a) Source # Methods toColumns :: NullTable context a -> Columns (NullTable context a) context' Source # fromColumns :: Columns (NullTable context a) context' -> NullTable context a Source # fromResult :: Columns (NullTable context a) Result -> FromExprs (NullTable context a) Source # toResult :: FromExprs (NullTable context a) -> Columns (NullTable context a) Result Source #
context ~ Expr => AltTable (NullTable context) Source #
Instance details Defined in Rel8.Table.Null Methods (<\|>:) :: Table Expr a => NullTable context a -> NullTable context a -> NullTable context a Source #
context ~ Expr => AlternativeTable (NullTable context) Source #
Instance details Defined in Rel8.Table.Null Methods emptyTable :: Table Expr a => NullTable context a Source #
Projectable (NullTable context) Source #
Instance details Defined in Rel8.Table.Null Methods project :: Projecting a b => Projection a b -> NullTable context a -> NullTable context b Source #
(EqTable a, context ~ Expr) => EqTable (NullTable context a) Source #
Instance details Defined in Rel8.Table.Null Methods eqTable :: Columns (NullTable context a) (Dict (Sql DBEq)) Source #
(OrdTable a, context ~ Expr) => OrdTable (NullTable context a) Source #
Instance details Defined in Rel8.Table.Null Methods ordTable :: Columns (NullTable context a) (Dict (Sql DBOrd)) Source #
(ToExprs exprs a, context ~ Expr) => ToExprs (NullTable context exprs) (Maybe a) Source #
Instance details Defined in Rel8.Table.Null
type Transpose to (NullTable context a) Source #
Instance details Defined in Rel8.Table.Null type Transpose to (NullTable context a) = NullTable to (Transpose to a)
type Columns (NullTable context a) Source #
Instance details Defined in Rel8.Table.Null type Columns (NullTable context a)
type Context (NullTable context a) Source #
Instance details Defined in Rel8.Table.Null type Context (NullTable context a)
type FromExprs (NullTable context a) Source #
Instance details Defined in Rel8.Table.Null type FromExprs (NullTable context a)

nullableTable :: (Table Expr a, Table Expr b) => b -> (a -> b) -> NullTable Expr a -> b Source #

Like nullable.

nullTable :: Table Expr a => NullTable Expr a Source #

The null table. Like null.

nullifyTable :: a -> NullTable Expr a Source #

Lift any table into NullTable. Like nullify.

isNullTable :: Table Expr a => NullTable Expr a -> Expr Bool Source #

Check if any of the non-nullable fields of a are null under the NullTable. Returns false if a has no non-nullable fields.

isNonNullTable :: Table Expr a => NullTable Expr a -> Expr Bool Source #

The inverse of isNullTable.

catNullTable :: Table Expr a => NullTable Expr a -> Query a Source #

Filter a Query that might return nullTable to a Query without any nullTables.

Corresponds to catMaybes.

nameNullTable :: a -> NullTable Name a Source #

Construct a NullTable in the Name context. This can be useful if you have a NullTable that you are storing in a table and need to construct a TableSchema.

toNullTable :: Table Expr a => MaybeTable Expr a -> NullTable Expr a Source #

Convert a MaybeTable to a NullTable. Note that if the underlying a has no non-nullable fields, this is a lossy conversion.

toMaybeTable :: Table Expr a => NullTable Expr a -> MaybeTable Expr a Source #

Convert a NullTable to a MaybeTable.

Algebraic data types / sum types

Algebraic data types can be modelled between Haskell and SQL.

Your SQL table needs a certain text field that tags which Haskell constructor is in use.
You have to use a few combinators to specify the sum type's individual constructors.
If you want to do case analysis at the Expr (SQL) level, you can use maybe/either-like eliminators.

The documentation in this section will assume a set of database types like this:

data Thing f = ThingEmployer (Employer f) | ThingPotato (Potato f) | Nullary
    deriving stock Generic

data Employer f = Employer { employerId :: f Int32, employerName :: f Text}
  deriving stock Generic
  deriving anyclass Rel8able

data Potato f = Potato { size :: f Int32, grower :: f Text }
  deriving stock Generic
  deriving anyclass Rel8able

Naming of ADTs

First, in your TableSchema, name your type like this:

thingSchema :: TableSchema (ADT Thing Name)
thingSchema =
  TableSchema
    { schema = Nothing,
      name = "thing",
      columns =
        nameADT @Thing
          "tag"
          Employer
            { employerName = "name",
              employerId = "id"
            }
          Potato {size = "size", grower = "Mary"}
    }

Note that nameADT @Thing "tag" is variadic: it accepts one argument per constructor, except the nullary ones (Nullary) because there's nothing to do for them.

type NameADT t = GGName 'Sum (ADTRep t) (ADT t Name) Source #

nameADT :: forall t. ConstructableADT t => NameADT t Source #

data ADT t context Source #

Instances

Instances details

ADTable t => Rel8able (ADT t) Source #

Instance details

Defined in Rel8.Table.ADT

Associated Types

type GColumns (ADT t) :: HTable

type GFromExprs (ADT t)

Methods

gfromColumns :: forall (context :: Context). SContext context -> GColumns (ADT t) context -> ADT t context

gtoColumns :: forall (context :: Context). SContext context -> ADT t context -> GColumns (ADT t) context

gfromResult :: GColumns (ADT t) Result -> GFromExprs (ADT t)

gtoResult :: GFromExprs (ADT t) -> GColumns (ADT t) Result

class (Generic (Record (t Result)), HTable (GColumnsADT t), GSerializeADT TSerialize TColumns (Eval (ADTRep t Expr)) (Eval (ADTRep t Result))) => ADTable t Source #

Instances

Instances details

(Generic (Record (t Result)), HTable (GColumnsADT t), GSerializeADT TSerialize TColumns (Eval (ADTRep t Expr)) (Eval (ADTRep t Result))) => ADTable t Source #
Instance details Defined in Rel8.Table.ADT

Deconstruction of ADTs

To deconstruct sum types at the SQL level, use deconstructADT, which is also variadic, and has one argument for each constructor. Similar to maybe.

query :: Query (ADT Thing Expr)
query = do
  thingExpr <- each thingSchema
  where_ $
    deconstructADT @Thing
      (employer -> employerName employer ==. lit "Mary")
      (potato -> grower potato ==. lit "Mary")
      (lit False) -- Nullary case
      thingExpr
  pure thingExpr

SQL output:

SELECT
CAST("tag0_1" AS text) as "tag",
CAST("id1_1" AS int4) as "ThingEmployer_1employerId",
CAST("name2_1" AS text) as "ThingEmployer_1employerName",
CAST("size3_1" AS int4) as "ThingPotato_1size",
CAST(Mary4_1 AS text) as "ThingPotato_1grower"
FROM (SELECT
      *
      FROM (SELECT
            "tag" as "tag0_1",
            "id" as "id1_1",
            "name" as "name2_1",
            "size" as "size3_1",
            Mary as Mary4_1
            FROM "thing" as T1) as T1
      WHERE (CASE WHEN ("tag0_1") = (CAST(EThingPotato AS text)) THEN (Mary4_1) = (CAST(EMary AS text))
                  WHEN ("tag0_1") = (CAST(ENullary AS text)) THEN CAST(FALSE AS bool) ELSE ("name2_1") = (CAST(EMary AS text)) END)) as T1

type DeconstructADT t r = GGDeconstruct 'Sum (ADTRep t) (ADT t Expr) r Source #

deconstructADT :: forall t r. (ConstructableADT t, Table Expr r) => DeconstructADT t r Source #

Construction of ADTs

To construct an ADT, you can use buildADT or constructADT. Consider the following type:

data Task f = Pending | Complete (CompletedTask f)

buildADT is for constructing values of Task in the Expr context. buildADT needs two type-level arguments before its type makes any sense. The first argument is the type of the ADT, which in our case is Task. The second is the name of the constructor we want to use. So that means we have the following possible instantiations of buildADT for Task:

> :t buildADT Task "Pending"
buildADT Task "Pending" :: ADT Task Expr
> :t buildADT Task "Complete"
buildADT Task "Complete" :: CompletedTask Expr -> ADT Task Expr

Note that as the Pending constructor has no fields, buildADT @Task @Pending is equivalent to lit Pending. But buildADT @Task @Complete is not the same as lit . Complete:

> :t lit . Complete
lit . Complete :: CompletedTask Result -> ADT Task Expr

Note that the former takes a CompletedTask Expr while the latter takes a CompletedTask Result. The former is more powerful because you can construct Tasks using dynamic values coming a database query.

To show what this can look like in SQL, consider:

> :{
showQuery $ values
  [ buildADT Task "Pending"
  , buildADT Task "Complete" CompletedTask {date = Rel8.Expr.Time.now}
  ]
:}

This produces the following SQL:

SELECT
CAST("values0_1" AS text) as "tag",
CAST("values1_1" AS timestamptz) as "Complete_1date"
FROM (SELECT
      *
      FROM (SELECT "column1" as "values0_1",
                   "column2" as "values1_1"
            FROM
            (VALUES
             (CAST(EPending AS text),CAST(NULL AS timestamptz)),
             (CAST(EComplete AS text),CAST(now() AS timestamptz))) as "V") as "T1") as "T1"

This is what you get if you run it in psql:

   tag    |       Complete_1date
----------+-------------------------------
 Pending  |
 Complete | 2022-05-19 21:28:23.969065+00
(2 rows)

"constructADT" is less convenient but more general alternative to "buildADT". It requires only one type-level argument for its type to make sense:

> :t constructADT Task
constructADT Task
  :: (forall r. r -> (CompletedTask Expr -> r) -> r) -> ADT Task Expr

This might still seem a bit opaque, but basically it gives you a Church-encoded constructor for arbitrary algebraic data types. You might use it as follows:

let
  pending :: ADT Task Expr
  pending = constructADT Task $ pending _complete -> pending

  complete :: ADT Task Expr
  complete = constructADT Task $ _pending complete -> complete CompletedTask {date = Rel8.Expr.Time.now}

These values are otherwise identical to the ones we saw above with buildADT, it's just a different style of constructing them.

type BuildADT t name = GGBuild 'Sum name (ADTRep t) (ADT t Expr) Source #

buildADT :: forall t name. BuildableADT t name => BuildADT t name Source #

type ConstructADT t = forall r. GGConstruct 'Sum (ADTRep t) r Source #

constructADT :: forall t. ConstructableADT t => ConstructADT t -> ADT t Expr Source #

Other ADT operations

type AggregateADT t = forall r. GGAggregate 'Sum (ADTRep t) r Source #

aggregateADT :: forall t. ConstructableADT t => AggregateADT t -> ADT t Expr -> ADT t Aggregate Source #

Miscellaneous notes

Note that the order of the arguments for all of these functions is determined by the order of the constructors in the data definition. If it were data Task = Complete (CompletedTask f) | Pending then the order of all the invocations of constructADT and deconstructADT would need to change.
Maybe this is obvious, but just to spell it out: once you're in the Result context, you can of course construct Task values normally and use standard Haskell pattern-matching. constructADT and deconstructADT are specifically only needed in the Expr context, and they allow you to do the equivalent of pattern matching in PostgreSQL.

`HKD`

data HKD a f Source #

Instances

Instances details

HKDable a => Rel8able (HKD a) Source #
Instance details Defined in Rel8.Table.HKD Associated Types type GColumns (HKD a) :: HTable type GFromExprs (HKD a) Methods gfromColumns :: forall (context :: Context). SContext context -> GColumns (HKD a) context -> HKD a context gtoColumns :: forall (context :: Context). SContext context -> HKD a context -> GColumns (HKD a) context gfromResult :: GColumns (HKD a) Result -> GFromExprs (HKD a) gtoResult :: GFromExprs (HKD a) -> GColumns (HKD a) Result
(GTable (TTable f) TColumns (GRecord (GMap (TColumn f) (Rep a))), GColumns TColumns (GRecord (GMap (TColumn f) (Rep a))) ~ GColumnsHKD a, GContext TContext (GRecord (GMap (TColumn f) (Rep a))) ~ f, GRecordable (GMap (TColumn f) (Rep a))) => Generic (HKD a f) Source #
Instance details Defined in Rel8.Table.HKD Associated Types type Rep (HKD a f) :: Type -> Type # Methods from :: HKD a f -> Rep (HKD a f) x # to :: Rep (HKD a f) x -> HKD a f #
type Rep (HKD a f) Source #
Instance details Defined in Rel8.Table.HKD type Rep (HKD a f)

class (Generic (Record a), HTable (GColumns (HKD a)), KnownAlgebra (GAlgebra (Rep a)), Eval (GGSerialize (GAlgebra (Rep a)) TSerialize TColumns (Eval (HKDRep a Expr)) (Eval (HKDRep a Result))), GRecord (GMap (TColumn Result) (Rep a)) ~ Rep (Record a)) => HKDable a Source #

Instances

Instances details

(Generic (Record a), HTable (GColumns (HKD a)), KnownAlgebra (GAlgebra (Rep a)), Eval (GGSerialize (GAlgebra (Rep a)) TSerialize TColumns (Eval (HKDRep a Expr)) (Eval (HKDRep a Result))), GRecord (GMap (TColumn Result) (Rep a)) ~ Rep (Record a)) => HKDable a Source #
Instance details Defined in Rel8.Table.HKD

type BuildHKD a name = GGBuild (GAlgebra (Rep a)) name (HKDRep a) (HKD a Expr) Source #

buildHKD :: forall a name. BuildableHKD a name => BuildHKD a name Source #

type ConstructHKD a = forall r. GGConstruct (GAlgebra (Rep a)) (HKDRep a) r Source #

constructHKD :: forall a. ConstructableHKD a => ConstructHKD a -> HKD a Expr Source #

type DeconstructHKD a r = GGDeconstruct (GAlgebra (Rep a)) (HKDRep a) (HKD a Expr) r Source #

deconstructHKD :: forall a r. (ConstructableHKD a, Table Expr r) => DeconstructHKD a r Source #

type NameHKD a = GGName (GAlgebra (Rep a)) (HKDRep a) (HKD a Name) Source #

nameHKD :: forall a. ConstructableHKD a => NameHKD a Source #

type AggregateHKD a = forall r. GGAggregate (GAlgebra (Rep a)) (HKDRep a) r Source #

aggregateHKD :: forall a. ConstructableHKD a => AggregateHKD a -> HKD a Expr -> HKD a Aggregate Source #

Table schemas

data TableSchema names Source #

The schema for a table. This is used to specify the name and schema that a table belongs to (the FROM part of a SQL query), along with the schema of the columns within this table.

For each selectable table in your database, you should provide a TableSchema in order to interact with the table via Rel8.

Constructors

TableSchema
Fields name :: String The name of the table. schema :: Maybe String The schema that this table belongs to. If `Nothing`, whatever is on the connection's `search_path` will be used. columns :: names The columns of the table. Typically you would use a a higher-kinded data type here, parameterized by the `ColumnSchema` functor.

Instances

Instances details

Functor TableSchema Source #
Instance details Defined in Rel8.Schema.Table Methods fmap :: (a -> b) -> TableSchema a -> TableSchema b # (<$) :: a -> TableSchema b -> TableSchema a #

data Name a Source #

A Name is the name of a column, as it would be defined in a table's schema definition. You can construct names by using the OverloadedStrings extension and writing string literals. This is typically done when providing a TableSchema value.

Instances

Instances details

Sql DBType a => Table Name (Name a) Source #
Instance details Defined in Rel8.Schema.Name Associated Types type Columns (Name a) :: HTable Source # type Context (Name a) :: Context Source # type FromExprs (Name a) Source # type Transpose context' (Name a) Source # Methods toColumns :: Name a -> Columns (Name a) Name Source # fromColumns :: Columns (Name a) Name -> Name a Source # fromResult :: Columns (Name a) Result -> FromExprs (Name a) Source # toResult :: FromExprs (Name a) -> Columns (Name a) Result Source #
IsString (Name a) Source #
Instance details Defined in Rel8.Schema.Name Methods fromString :: String -> Name a #
Show (Name a) Source #
Instance details Defined in Rel8.Schema.Name Methods showsPrec :: Int -> Name a -> ShowS # show :: Name a -> String # showList :: [Name a] -> ShowS #
type Transpose to (Name a) Source #
Instance details Defined in Rel8.Schema.Name type Transpose to (Name a) = to a
type Columns (Name a) Source #
Instance details Defined in Rel8.Schema.Name type Columns (Name a)
type Context (Name a) Source #
Instance details Defined in Rel8.Schema.Name type Context (Name a) = Name
type FromExprs (Name a) Source #
Instance details Defined in Rel8.Schema.Name type FromExprs (Name a) = a

namesFromLabels :: Table Name a => a Source #

Construct a table in the Name context containing the names of all columns. Nested column names will be combined with /.

Expressions

data Expr a Source #

Typed SQL expressions.

Instances

Instances details

(arg ~ Expr a, Sql DBType b) => Function arg (Expr b) Source #
Instance details Defined in Rel8.Expr.Function Methods applyArgument :: ([PrimExpr] -> PrimExpr) -> arg -> Expr b
Sql DBType a => Table Expr (Expr a) Source #
Instance details Defined in Rel8.Expr Associated Types type Columns (Expr a) :: HTable Source # type Context (Expr a) :: Context Source # type FromExprs (Expr a) Source # type Transpose context' (Expr a) Source # Methods toColumns :: Expr a -> Columns (Expr a) Expr Source # fromColumns :: Columns (Expr a) Expr -> Expr a Source # fromResult :: Columns (Expr a) Result -> FromExprs (Expr a) Source # toResult :: FromExprs (Expr a) -> Columns (Expr a) Result Source #
(Sql IsString a, Sql DBType a) => IsString (Expr a) Source #
Instance details Defined in Rel8.Expr Methods fromString :: String -> Expr a #
Sql DBMonoid a => Monoid (Expr a) Source #
Instance details Defined in Rel8.Expr Methods mempty :: Expr a # mappend :: Expr a -> Expr a -> Expr a # mconcat :: [Expr a] -> Expr a #
Sql DBSemigroup a => Semigroup (Expr a) Source #
Instance details Defined in Rel8.Expr Methods (<>) :: Expr a -> Expr a -> Expr a # sconcat :: NonEmpty (Expr a) -> Expr a # stimes :: Integral b => b -> Expr a -> Expr a #
Sql DBFloating a => Floating (Expr a) Source #
Instance details Defined in Rel8.Expr Methods pi :: Expr a # exp :: Expr a -> Expr a # log :: Expr a -> Expr a # sqrt :: Expr a -> Expr a # (**) :: Expr a -> Expr a -> Expr a # logBase :: Expr a -> Expr a -> Expr a # sin :: Expr a -> Expr a # cos :: Expr a -> Expr a # tan :: Expr a -> Expr a # asin :: Expr a -> Expr a # acos :: Expr a -> Expr a # atan :: Expr a -> Expr a # sinh :: Expr a -> Expr a # cosh :: Expr a -> Expr a # tanh :: Expr a -> Expr a # asinh :: Expr a -> Expr a # acosh :: Expr a -> Expr a # atanh :: Expr a -> Expr a # log1p :: Expr a -> Expr a # expm1 :: Expr a -> Expr a # log1pexp :: Expr a -> Expr a # log1mexp :: Expr a -> Expr a #
Sql DBNum a => Num (Expr a) Source #
Instance details Defined in Rel8.Expr Methods (+) :: Expr a -> Expr a -> Expr a # (-) :: Expr a -> Expr a -> Expr a # (*) :: Expr a -> Expr a -> Expr a # negate :: Expr a -> Expr a # abs :: Expr a -> Expr a # signum :: Expr a -> Expr a # fromInteger :: Integer -> Expr a #
Sql DBFractional a => Fractional (Expr a) Source #
Instance details Defined in Rel8.Expr Methods (/) :: Expr a -> Expr a -> Expr a # recip :: Expr a -> Expr a # fromRational :: Rational -> Expr a #
Show (Expr a) Source #
Instance details Defined in Rel8.Expr Methods showsPrec :: Int -> Expr a -> ShowS # show :: Expr a -> String # showList :: [Expr a] -> ShowS #
Sql DBEq a => EqTable (Expr a) Source #
Instance details Defined in Rel8.Table.Eq Methods eqTable :: Columns (Expr a) (Dict (Sql DBEq)) Source #
Sql DBOrd a => OrdTable (Expr a) Source #
Instance details Defined in Rel8.Table.Ord Methods ordTable :: Columns (Expr a) (Dict (Sql DBOrd)) Source #
Sql DBType a => Serializable (Expr a) a Source #
Instance details Defined in Rel8.Table.Serialize
(Sql DBType a, NotNull a, x ~ NonEmpty a) => ToExprs (Expr x) (NonEmpty a) Source #
Instance details Defined in Rel8.Table.Serialize
(Sql DBType a, NotNull a, x ~ Maybe a) => ToExprs (Expr x) (Maybe a) Source #
Instance details Defined in Rel8.Table.Serialize
(Sql DBType a, x ~ [a]) => ToExprs (Expr x) [a] Source #
Instance details Defined in Rel8.Table.Serialize
type Transpose to (Expr a) Source #
Instance details Defined in Rel8.Expr type Transpose to (Expr a) = to a
type Columns (Expr a) Source #
Instance details Defined in Rel8.Expr type Columns (Expr a)
type Context (Expr a) Source #
Instance details Defined in Rel8.Expr type Context (Expr a) = Expr
type FromExprs (Expr a) Source #
Instance details Defined in Rel8.Expr type FromExprs (Expr a) = a

class (constraint (Unnullify a), Nullable a) => Sql constraint a Source #

The Sql type class describes both null and not null database values, constrained by a specific class.

For example, if you see Sql DBEq a, this means any database type that supports equality, and a can either be exactly an a, or it could also be Maybe a.

Instances

Instances details

(constraint (Unnullify a), Nullable a) => Sql constraint a Source #
Instance details Defined in Rel8.Schema.Null

litExpr :: Sql DBType a => a -> Expr a Source #

Produce an expression from a literal.

Note that you can usually use lit, but litExpr can solve problems of inference in polymorphic code.

unsafeCastExpr :: Sql DBType b => Expr a -> Expr b Source #

Cast an expression to a different type. Corresponds to a CAST() function call.

unsafeLiteral :: String -> Expr a Source #

Unsafely construct an expression from literal SQL.

This is an escape hatch, and can be used if Rel8 can not adequately express the query you need. If you find yourself using this function, please let us know, as it may indicate that something is missing from Rel8!

`null`

class (Nullable a, IsMaybe a ~ 'False) => NotNull a Source #

nullify a means a cannot take null as a value.

Instances

Instances details

(Nullable a, IsMaybe a ~ 'False) => NotNull a Source #
Instance details Defined in Rel8.Schema.Null

class Nullable' (IsMaybe a) a => Nullable a Source #

Nullable a means that rel8 is able to check if the type a is a type that can take null values or not.

Instances

Instances details

Nullable' (IsMaybe a) a => Nullable a Source #
Instance details Defined in Rel8.Schema.Null

class IsMaybe a ~ IsMaybe b => Homonullable a b Source #

Homonullable a b means that both a and b can be null, or neither a or b can be null.

Instances

Instances details

IsMaybe a ~ IsMaybe b => Homonullable a b Source #
Instance details Defined in Rel8.Schema.Null

null :: DBType a => Expr (Maybe a) Source #

Corresponds to SQL null.

nullify :: NotNull a => Expr a -> Expr (Maybe a) Source #

Lift an expression that can't be null to a type that might be null. This is an identity operation in terms of any generated query, and just modifies the query's type.

nullable :: Table Expr b => b -> (Expr a -> b) -> Expr (Maybe a) -> b Source #

Like maybe, but to eliminate null.

isNull :: Expr (Maybe a) -> Expr Bool Source #

Like isNothing, but for null.

isNonNull :: Expr (Maybe a) -> Expr Bool Source #

Like isJust, but for null.

mapNull :: DBType b => (Expr a -> Expr b) -> Expr (Maybe a) -> Expr (Maybe b) Source #

Lift an operation on non-null values to an operation on possibly null values. When given null, mapNull f returns null.

This is like fmap for Maybe.

liftOpNull :: DBType c => (Expr a -> Expr b -> Expr c) -> Expr (Maybe a) -> Expr (Maybe b) -> Expr (Maybe c) Source #

Lift a binary operation on non-null expressions to an equivalent binary operator on possibly null expressions. If either of the final arguments are null, liftOpNull returns null.

This is like liftA2 for Maybe.

catNull :: Expr (Maybe a) -> Query (Expr a) Source #

Filter a Query that might return null to a Query without any nulls.

Corresponds to catMaybes.

coalesce :: Expr (Maybe Bool) -> Expr Bool Source #

Convert a Expr (Maybe Bool) to a Expr Bool by treating Nothing as False. This can be useful when combined with where_, which expects a Bool, and produces expressions that optimize better than general case analysis.

Boolean operations

class DBType a => DBEq a Source #

Database types that can be compared for equality in queries. If a type is an instance of DBEq, it means we can compare expressions for equality using the SQL = operator.

Instances

Instances details

DBEq Value Source #
Instance details Defined in Rel8.Type.Eq
DBEq Int16 Source #
Instance details Defined in Rel8.Type.Eq
DBEq Int32 Source #
Instance details Defined in Rel8.Type.Eq
DBEq Int64 Source #
Instance details Defined in Rel8.Type.Eq
DBEq ByteString Source #
Instance details Defined in Rel8.Type.Eq
DBEq ByteString Source #
Instance details Defined in Rel8.Type.Eq
DBEq Scientific Source #
Instance details Defined in Rel8.Type.Eq
DBEq Text Source #
Instance details Defined in Rel8.Type.Eq
DBEq Text Source #
Instance details Defined in Rel8.Type.Eq
DBEq Day Source #
Instance details Defined in Rel8.Type.Eq
DBEq UTCTime Source #
Instance details Defined in Rel8.Type.Eq
DBEq CalendarDiffTime Source #
Instance details Defined in Rel8.Type.Eq
DBEq LocalTime Source #
Instance details Defined in Rel8.Type.Eq
DBEq TimeOfDay Source #
Instance details Defined in Rel8.Type.Eq
DBEq UUID Source #
Instance details Defined in Rel8.Type.Eq
DBEq Bool Source #
Instance details Defined in Rel8.Type.Eq
DBEq Char Source #
Instance details Defined in Rel8.Type.Eq
DBEq Double Source #
Instance details Defined in Rel8.Type.Eq
DBEq Float Source #
Instance details Defined in Rel8.Type.Eq
DBEq (CI Text) Source #
Instance details Defined in Rel8.Type.Eq
DBEq (CI Text) Source #
Instance details Defined in Rel8.Type.Eq
(DBComposite a, EqTable (HKD a Expr)) => DBEq (Composite a) Source #
Instance details Defined in Rel8.Type.Composite
DBEnum a => DBEq (Enum a) Source #
Instance details Defined in Rel8.Type.Enum
Sql DBEq a => DBEq (NonEmpty a) Source #
Instance details Defined in Rel8.Type.Eq
Sql DBEq a => DBEq [a] Source #
Instance details Defined in Rel8.Type.Eq

true :: Expr Bool Source #

The SQL true literal.

false :: Expr Bool Source #

The SQL false literal.

not_ :: Expr Bool -> Expr Bool Source #

The SQL NOT operator.

(&&.) :: Expr Bool -> Expr Bool -> Expr Bool infixr 3 Source #

The SQL AND operator.

and_ :: Foldable f => f (Expr Bool) -> Expr Bool Source #

Fold AND over a collection of expressions.

(||.) :: Expr Bool -> Expr Bool -> Expr Bool infixr 2 Source #

The SQL OR operator.

or_ :: Foldable f => f (Expr Bool) -> Expr Bool Source #

Fold OR over a collection of expressions.

(==.) :: forall a. Sql DBEq a => Expr a -> Expr a -> Expr Bool infix 4 Source #

Compare two expressions for equality.

This corresponds to the SQL IS NOT DISTINCT FROM operator, and will equate null values as true. This differs from = which would return null. This operator matches Haskell's == operator. For an operator identical to SQL =, see ==?.

(/=.) :: forall a. Sql DBEq a => Expr a -> Expr a -> Expr Bool infix 4 Source #

Test if two expressions are different (not equal).

This corresponds to the SQL IS DISTINCT FROM operator, and will return false when comparing two null values. This differs from ordinary = which would return null. This operator is closer to Haskell's == operator. For an operator identical to SQL =, see /=?.

(==?) :: DBEq a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool infix 4 Source #

Test if two expressions are equal. This operator is usually the best choice when forming join conditions, as PostgreSQL has a much harder time optimizing a join that has multiple True conditions.

This corresponds to the SQL = operator, though it will always return a Bool.

(/=?) :: DBEq a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool infix 4 Source #

Test if two expressions are different.

This corresponds to the SQL <> operator, though it will always return a Bool.

in_ :: forall a f. (Sql DBEq a, Foldable f) => Expr a -> f (Expr a) -> Expr Bool Source #

Like the SQL IN operator, but implemented by folding over a list with ==. and ||..

boolExpr :: Expr a -> Expr a -> Expr Bool -> Expr a Source #

Eliminate a boolean-valued expression.

Corresponds to bool.

caseExpr :: [(Expr Bool, Expr a)] -> Expr a -> Expr a Source #

A multi-way ifthenelse statement. The first argument to caseExpr is a list of alternatives. The first alternative that is of the form (true, x) will be returned. If no such alternative is found, a fallback expression is returned.

Corresponds to a CASE expression in SQL.

like :: Expr Text -> Expr Text -> Expr Bool Source #

like x y corresponds to the expression y LIKE x.

Note that the arguments to like are swapped. This is to aid currying, so you can write expressions like filter (like "Rel%" . packageName) =<< each haskellPackages

ilike :: Expr Text -> Expr Text -> Expr Bool Source #

ilike x y corresponds to the expression y ILIKE x.

Note that the arguments to ilike are swapped. This is to aid currying, so you can write expressions like filter (ilike "Rel%" . packageName) =<< each haskellPackages

Ordering

class DBEq a => DBOrd a Source #

The class of database types that support the <, <=, > and >= operators.

Instances

Instances details

DBOrd Int16 Source #
Instance details Defined in Rel8.Type.Ord
DBOrd Int32 Source #
Instance details Defined in Rel8.Type.Ord
DBOrd Int64 Source #
Instance details Defined in Rel8.Type.Ord
DBOrd ByteString Source #
Instance details Defined in Rel8.Type.Ord
DBOrd ByteString Source #
Instance details Defined in Rel8.Type.Ord
DBOrd Scientific Source #
Instance details Defined in Rel8.Type.Ord
DBOrd Text Source #
Instance details Defined in Rel8.Type.Ord
DBOrd Text Source #
Instance details Defined in Rel8.Type.Ord
DBOrd Day Source #
Instance details Defined in Rel8.Type.Ord
DBOrd UTCTime Source #
Instance details Defined in Rel8.Type.Ord
DBOrd CalendarDiffTime Source #
Instance details Defined in Rel8.Type.Ord
DBOrd LocalTime Source #
Instance details Defined in Rel8.Type.Ord
DBOrd TimeOfDay Source #
Instance details Defined in Rel8.Type.Ord
DBOrd UUID Source #
Instance details Defined in Rel8.Type.Ord
DBOrd Bool Source #
Instance details Defined in Rel8.Type.Ord
DBOrd Char Source #
Instance details Defined in Rel8.Type.Ord
DBOrd Double Source #
Instance details Defined in Rel8.Type.Ord
DBOrd Float Source #
Instance details Defined in Rel8.Type.Ord
DBOrd (CI Text) Source #
Instance details Defined in Rel8.Type.Ord
DBOrd (CI Text) Source #
Instance details Defined in Rel8.Type.Ord
(DBComposite a, OrdTable (HKD a Expr)) => DBOrd (Composite a) Source #
Instance details Defined in Rel8.Type.Composite
DBEnum a => DBOrd (Enum a) Source #
Instance details Defined in Rel8.Type.Enum
Sql DBOrd a => DBOrd (NonEmpty a) Source #
Instance details Defined in Rel8.Type.Ord
Sql DBOrd a => DBOrd [a] Source #
Instance details Defined in Rel8.Type.Ord

(<.) :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr Bool infix 4 Source #

Corresponds to the SQL < operator. Note that this differs from SQL < as null will sort below any other value. For a version of < that exactly matches SQL, see (<?).

(<=.) :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr Bool infix 4 Source #

Corresponds to the SQL <= operator. Note that this differs from SQL <= as null will sort below any other value. For a version of <= that exactly matches SQL, see (<=?).

(>.) :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr Bool infix 4 Source #

Corresponds to the SQL > operator. Note that this differs from SQL > as null will sort below any other value. For a version of > that exactly matches SQL, see (>?).

(>=.) :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr Bool infix 4 Source #

Corresponds to the SQL >= operator. Note that this differs from SQL > as null will sort below any other value. For a version of >= that exactly matches SQL, see (>=?).

(<?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool infix 4 Source #

Corresponds to the SQL < operator. Returns null if either arguments are null.

(<=?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool infix 4 Source #

Corresponds to the SQL <= operator. Returns null if either arguments are null.

(>?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool infix 4 Source #

Corresponds to the SQL > operator. Returns null if either arguments are null.

(>=?) :: DBOrd a => Expr (Maybe a) -> Expr (Maybe a) -> Expr Bool infix 4 Source #

Corresponds to the SQL >= operator. Returns null if either arguments are null.

leastExpr :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr a Source #

Given two expressions, return the expression that sorts less than the other.

Corresponds to the SQL least() function.

greatestExpr :: forall a. Sql DBOrd a => Expr a -> Expr a -> Expr a Source #

Given two expressions, return the expression that sorts greater than the other.

Corresponds to the SQL greatest() function.

Functions

class Function arg res Source #

This type class exists to allow function to have arbitrary arity. It's mostly an implementation detail, and typical uses of Function shouldn't need this to be specified.

Minimal complete definition

applyArgument

Instances

Instances details

(arg ~ Expr a, Sql DBType b) => Function arg (Expr b) Source #
Instance details Defined in Rel8.Expr.Function Methods applyArgument :: ([PrimExpr] -> PrimExpr) -> arg -> Expr b
(arg ~ Expr a, Function args res) => Function arg (args -> res) Source #
Instance details Defined in Rel8.Expr.Function Methods applyArgument :: ([PrimExpr] -> PrimExpr) -> arg -> args -> res

function :: Function args result => String -> args -> result Source #

Construct an n-ary function that produces an Expr that when called runs a SQL function.

nullaryFunction :: Sql DBType a => String -> Expr a Source #

Construct a function call for functions with no arguments.

binaryOperator :: Sql DBType c => String -> Expr a -> Expr b -> Expr c Source #

Construct an expression by applying an infix binary operator to two operands.

Queries

data Query a Source #

The Query monad allows you to compose a SELECT query. This monad has semantics similar to the list ([]) monad.

Instances

Instances details

Applicative Query Source #
Instance details Defined in Rel8.Query Methods pure :: a -> Query a # (<>) :: Query (a -> b) -> Query a -> Query b # liftA2 :: (a -> b -> c) -> Query a -> Query b -> Query c # (>) :: Query a -> Query b -> Query b # (<*) :: Query a -> Query b -> Query a #
Functor Query Source #
Instance details Defined in Rel8.Query Methods fmap :: (a -> b) -> Query a -> Query b # (<$) :: a -> Query b -> Query a #
Monad Query Source #
Instance details Defined in Rel8.Query Methods (>>=) :: Query a -> (a -> Query b) -> Query b # (>>) :: Query a -> Query b -> Query b # return :: a -> Query a #
AltTable Query Source #	`<\|>:` = `unionAll`.
Instance details Defined in Rel8.Query Methods (<\|>:) :: Table Expr a => Query a -> Query a -> Query a Source #
AlternativeTable Query Source #	`emptyTable` = `values` `[]`.
Instance details Defined in Rel8.Query Methods emptyTable :: Table Expr a => Query a Source #
Projectable Query Source #
Instance details Defined in Rel8.Query Methods project :: Projecting a b => Projection a b -> Query a -> Query b Source #
Apply Query Source #
Instance details Defined in Rel8.Query Methods (<.>) :: Query (a -> b) -> Query a -> Query b # (.>) :: Query a -> Query b -> Query b # (<.) :: Query a -> Query b -> Query a # liftF2 :: (a -> b -> c) -> Query a -> Query b -> Query c #
Bind Query Source #
Instance details Defined in Rel8.Query Methods (>>-) :: Query a -> (a -> Query b) -> Query b # join :: Query (Query a) -> Query a #
Table Expr a => Monoid (Query a) Source #	`mempty` = `values []`.
Instance details Defined in Rel8.Query Methods mempty :: Query a # mappend :: Query a -> Query a -> Query a # mconcat :: [Query a] -> Query a #
Table Expr a => Semigroup (Query a) Source #	`<>` = `unionAll`.
Instance details Defined in Rel8.Query Methods (<>) :: Query a -> Query a -> Query a # sconcat :: NonEmpty (Query a) -> Query a # stimes :: Integral b => b -> Query a -> Query a #

showQuery :: Table Expr a => Query a -> String Source #

Convert a Query to a String containing a SELECT statement.

Projection

type Projection a b = Transpose (Field a) a -> Transpose (Field a) b Source #

A Projection a bs is a special type of function a -> b whereby the resulting b is guaranteed to be composed only from columns contained in a.

class Projectable f where Source #

Projectable f means that f is a kind of functor on Tables that allows the mapping of a Projection over its underlying columns.

Methods

project :: Projecting a b => Projection a b -> f a -> f b Source #

Map a Projection over f.

Instances

Instances details

Projectable Query Source #
Instance details Defined in Rel8.Query Methods project :: Projecting a b => Projection a b -> Query a -> Query b Source #
Projectable (ListTable context) Source #
Instance details Defined in Rel8.Table.List Methods project :: Projecting a b => Projection a b -> ListTable context a -> ListTable context b Source #
Projectable (MaybeTable context) Source #
Instance details Defined in Rel8.Table.Maybe Methods project :: Projecting a b => Projection a b -> MaybeTable context a -> MaybeTable context b Source #
Projectable (NonEmptyTable context) Source #
Instance details Defined in Rel8.Table.NonEmpty Methods project :: Projecting a b => Projection a b -> NonEmptyTable context a -> NonEmptyTable context b Source #
Projectable (NullTable context) Source #
Instance details Defined in Rel8.Table.Null Methods project :: Projecting a b => Projection a b -> NullTable context a -> NullTable context b Source #
Projectable (Tabulation k) Source #
Instance details Defined in Rel8.Tabulate Methods project :: Projecting a b => Projection a b -> Tabulation k a -> Tabulation k b Source #
Projectable (EitherTable context a) Source #
Instance details Defined in Rel8.Table.Either Methods project :: Projecting a0 b => Projection a0 b -> EitherTable context a a0 -> EitherTable context a b Source #
Projectable (TheseTable context a) Source #
Instance details Defined in Rel8.Table.These Methods project :: Projecting a0 b => Projection a0 b -> TheseTable context a a0 -> TheseTable context a b Source #

class Biprojectable p where Source #

Biprojectable p means that p is a kind of bifunctor on Tables that allows the mapping of a pair of Projections over its underlying columns.

Methods

biproject :: (Projecting a b, Projecting c d) => Projection a b -> Projection c d -> p a c -> p b d Source #

Map a pair of Projections over p.

Instances

Instances details

Biprojectable Tabulation Source #
Instance details Defined in Rel8.Tabulate Methods biproject :: (Projecting a b, Projecting c d) => Projection a b -> Projection c d -> Tabulation a c -> Tabulation b d Source #
Biprojectable (EitherTable context) Source #
Instance details Defined in Rel8.Table.Either Methods biproject :: (Projecting a b, Projecting c d) => Projection a b -> Projection c d -> EitherTable context a c -> EitherTable context b d Source #
Biprojectable (TheseTable context) Source #
Instance details Defined in Rel8.Table.These Methods biproject :: (Projecting a b, Projecting c d) => Projection a b -> Projection c d -> TheseTable context a c -> TheseTable context b d Source #

class (Transposes (Context a) (Field a) a (Transpose (Field a) a), Transposes (Context a) (Field a) b (Transpose (Field a) b)) => Projecting a b Source #

The constraint Projecting a b ensures that Projection a b is a usable Projection.

Instances

Instances details

(Transposes (Context a) (Field a) a (Transpose (Field a) a), Transposes (Context a) (Field a) b (Transpose (Field a) b)) => Projecting a b Source #
Instance details Defined in Rel8.Table.Projection

data Field table a Source #

A special context used in the construction of Projections.

Instances

Instances details

Sql DBType a => Table (Field table) (Field table a) Source #
Instance details Defined in Rel8.Schema.Field Associated Types type Columns (Field table a) :: HTable Source # type Context (Field table a) :: Context Source # type FromExprs (Field table a) Source # type Transpose context' (Field table a) Source # Methods toColumns :: Field table a -> Columns (Field table a) (Field table) Source # fromColumns :: Columns (Field table a) (Field table) -> Field table a Source # fromResult :: Columns (Field table a) Result -> FromExprs (Field table a) Source # toResult :: FromExprs (Field table a) -> Columns (Field table a) Result Source #
type Transpose to (Field table a) Source #
Instance details Defined in Rel8.Schema.Field type Transpose to (Field table a) = to a
type Columns (Field table a) Source #
Instance details Defined in Rel8.Schema.Field type Columns (Field table a)
type Context (Field table a) Source #
Instance details Defined in Rel8.Schema.Field type Context (Field table a) = Field table
type FromExprs (Field table a) Source #
Instance details Defined in Rel8.Schema.Field type FromExprs (Field table a) = a

Selecting rows

class Transposes Name Expr names exprs => Selects names exprs Source #

Selects a b means that a is a schema (i.e., a Table of Names) for the Expr columns in b.

Instances

Instances details

Transposes Name Expr names exprs => Selects names exprs Source #
Instance details Defined in Rel8.Schema.Name

each :: Selects names exprs => TableSchema names -> Query exprs Source #

Select each row from a table definition. This is equivalent to FROM table.

values :: (Table Expr a, Foldable f) => f a -> Query a Source #

Construct a query that returns the given input list of rows. This is like folding a list of return statements under union, but uses the SQL VALUES expression for efficiency.

Filtering

filter :: (a -> Expr Bool) -> a -> Query a Source #

filter f x will be a zero-row query when f x is False, and will return x unchanged when f x is True. This is similar to guard, but as the predicate is separate from the argument, it is easy to use in a pipeline of Query transformations.

where_ :: Expr Bool -> Query () Source #

Drop any rows that don't match a predicate. where_ expr is equivalent to the SQL WHERE expr.

present :: Query a -> Query () Source #

Produce the empty query if the given query returns no rows. present is equivalent to WHERE EXISTS in SQL.

absent :: Query a -> Query () Source #

Produce the empty query if the given query returns rows. absent is equivalent to WHERE NOT EXISTS in SQL.

distinct :: EqTable a => Query a -> Query a Source #

Select all distinct rows from a query, removing duplicates. distinct q is equivalent to the SQL statement SELECT DISTINCT q.

distinctOn :: EqTable b => (a -> b) -> Query a -> Query a Source #

Select all distinct rows from a query, where rows are equivalent according to a projection. If multiple rows have the same projection, it is unspecified which row will be returned. If this matters, use distinctOnBy.

distinctOnBy :: EqTable b => (a -> b) -> Order a -> Query a -> Query a Source #

Select all distinct rows from a query, where rows are equivalent according to a projection. If there are multiple rows with the same projection, the first row according to the specified Order will be returned.

`LIMIT`/`OFFSET`

limit :: Word -> Query a -> Query a Source #

limit n select at most n rows from a query. limit n is equivalent to the SQL LIMIT n.

offset :: Word -> Query a -> Query a Source #

offset n drops the first n rows from a query. offset n is equivalent to the SQL OFFSET n.

`UNION`

union :: EqTable a => Query a -> Query a -> Query a Source #

Combine the results of two queries of the same type, collapsing duplicates. union a b is the same as the SQL statement a UNION b.

unionAll :: Table Expr a => Query a -> Query a -> Query a Source #

Combine the results of two queries of the same type, retaining duplicates. unionAll a b is the same as the SQL statement a UNION ALL b.

`INTERSECT`

intersect :: EqTable a => Query a -> Query a -> Query a Source #

Find the intersection of two queries, collapsing duplicates. intersect a b is the same as the SQL statement a INTERSECT b.

intersectAll :: EqTable a => Query a -> Query a -> Query a Source #

Find the intersection of two queries, retaining duplicates. intersectAll a b is the same as the SQL statement a INTERSECT ALL b.

`EXCEPT`

except :: EqTable a => Query a -> Query a -> Query a Source #

Find the difference of two queries, collapsing duplicates except a b is the same as the SQL statement a EXCEPT b.

exceptAll :: EqTable a => Query a -> Query a -> Query a Source #

Find the difference of two queries, retaining duplicates. exceptAll a b is the same as the SQL statement a EXCEPT ALL b.

`EXISTS`

exists :: Query a -> Query (Expr Bool) Source #

Checks if a query returns at least one row.

with :: (a -> Query b) -> a -> Query a Source #

with is similar to filter, but allows the predicate to be a full query.

with f a = a <$ present (f a), but this form matches filter.

withBy :: (a -> b -> Expr Bool) -> Query b -> a -> Query a Source #

Like with, but with a custom membership test.

without :: (a -> Query b) -> a -> Query a Source #

Filter rows where a -> Query b yields no rows.

withoutBy :: (a -> b -> Expr Bool) -> Query b -> a -> Query a Source #

Like without, but with a custom membership test.

Aggregation

data Aggregate a Source #

Aggregate is a special context used by aggregate.

Instances

Instances details

Sql DBType a => Table Aggregate (Aggregate a) Source #
Instance details Defined in Rel8.Aggregate Associated Types type Columns (Aggregate a) :: HTable Source # type Context (Aggregate a) :: Context Source # type FromExprs (Aggregate a) Source # type Transpose context' (Aggregate a) Source # Methods toColumns :: Aggregate a -> Columns (Aggregate a) Aggregate Source # fromColumns :: Columns (Aggregate a) Aggregate -> Aggregate a Source # fromResult :: Columns (Aggregate a) Result -> FromExprs (Aggregate a) Source # toResult :: FromExprs (Aggregate a) -> Columns (Aggregate a) Result Source #
type Transpose to (Aggregate a) Source #
Instance details Defined in Rel8.Aggregate type Transpose to (Aggregate a) = to a
type Columns (Aggregate a) Source #
Instance details Defined in Rel8.Aggregate type Columns (Aggregate a)
type Context (Aggregate a) Source #
Instance details Defined in Rel8.Aggregate type Context (Aggregate a) = Aggregate
type FromExprs (Aggregate a) Source #
Instance details Defined in Rel8.Aggregate type FromExprs (Aggregate a) = a

class Transposes Aggregate Expr aggregates exprs => Aggregates aggregates exprs Source #

Aggregates a b means that the columns in a are all Aggregates for the Expr columns in b.

Instances

Instances details

Transposes Aggregate Expr aggregates exprs => Aggregates aggregates exprs Source #
Instance details Defined in Rel8.Aggregate

aggregate :: Aggregates aggregates exprs => Query aggregates -> Query exprs Source #

Apply an aggregation to all rows returned by a Query.

countRows :: Query a -> Query (Expr Int64) Source #

Count the number of rows returned by a query. Note that this is different from countStar, as even if the given query yields no rows, countRows will return 0.

groupBy :: forall exprs aggregates. (EqTable exprs, Aggregates aggregates exprs) => exprs -> aggregates Source #

Group equal tables together. This works by aggregating each column in the given table with groupByExpr.

For example, if we have a table of items, we could group the items by the order they belong to:

itemsByOrder :: Query (OrderId Expr, ListTable Expr (Item Expr))
itemsByOrder = aggregate $ do
  item <- each itemSchema
  let orderId = groupBy (itemOrderId item)
  let orderItems = listAgg item
  pure (orderId, orderItems)

listAgg :: Aggregates aggregates exprs => exprs -> ListTable Aggregate aggregates Source #

Aggregate rows into a single row containing an array of all aggregated rows. This can be used to associate multiple rows with a single row, without changing the over cardinality of the query. This allows you to essentially return a tree-like structure from queries.

For example, if we have a table of orders and each orders contains multiple items, we could aggregate the table of orders, pairing each order with its items:

ordersWithItems :: Query (Order Expr, ListTable Expr (Item Expr))
ordersWithItems = do
  order <- each orderSchema
  items aggregate $ listAgg <$ itemsFromOrder order
  return (order, items)

listAggExpr :: Sql DBType a => Expr a -> Aggregate [a] Source #

Collect expressions values as a list.

mode :: forall a. EqTable a => Query a -> Query a Source #

Return the most common row in a query.

nonEmptyAgg :: Aggregates aggregates exprs => exprs -> NonEmptyTable Aggregate aggregates Source #

Like listAgg, but the result is guaranteed to be a non-empty list.

nonEmptyAggExpr :: Sql DBType a => Expr a -> Aggregate (NonEmpty a) Source #

Collect expressions values as a non-empty list.

class DBOrd a => DBMax a Source #

The class of database types that support the max aggregation function.

Instances

Instances details

DBMax Int16 Source #
Instance details Defined in Rel8.Type.Ord
DBMax Int32 Source #
Instance details Defined in Rel8.Type.Ord
DBMax Int64 Source #
Instance details Defined in Rel8.Type.Ord
DBMax ByteString Source #
Instance details Defined in Rel8.Type.Ord
DBMax ByteString Source #
Instance details Defined in Rel8.Type.Ord
DBMax Scientific Source #
Instance details Defined in Rel8.Type.Ord
DBMax Text Source #
Instance details Defined in Rel8.Type.Ord
DBMax Text Source #
Instance details Defined in Rel8.Type.Ord
DBMax Day Source #
Instance details Defined in Rel8.Type.Ord
DBMax UTCTime Source #
Instance details Defined in Rel8.Type.Ord
DBMax CalendarDiffTime Source #
Instance details Defined in Rel8.Type.Ord
DBMax LocalTime Source #
Instance details Defined in Rel8.Type.Ord
DBMax TimeOfDay Source #
Instance details Defined in Rel8.Type.Ord
DBMax Char Source #
Instance details Defined in Rel8.Type.Ord
DBMax Double Source #
Instance details Defined in Rel8.Type.Ord
DBMax Float Source #
Instance details Defined in Rel8.Type.Ord
DBMax (CI Text) Source #
Instance details Defined in Rel8.Type.Ord
DBMax (CI Text) Source #
Instance details Defined in Rel8.Type.Ord
(DBComposite a, OrdTable (HKD a Expr)) => DBMax (Composite a) Source #
Instance details Defined in Rel8.Type.Composite
DBEnum a => DBMax (Enum a) Source #
Instance details Defined in Rel8.Type.Enum
Sql DBMax a => DBMax (NonEmpty a) Source #
Instance details Defined in Rel8.Type.Ord
Sql DBMax a => DBMax [a] Source #
Instance details Defined in Rel8.Type.Ord

max :: Sql DBMax a => Expr a -> Aggregate a Source #

Produce an aggregation for Expr a using the max function.

class DBOrd a => DBMin a Source #

The class of database types that support the min aggregation function.

Instances

Instances details

DBMin Int16 Source #
Instance details Defined in Rel8.Type.Ord
DBMin Int32 Source #
Instance details Defined in Rel8.Type.Ord
DBMin Int64 Source #
Instance details Defined in Rel8.Type.Ord
DBMin ByteString Source #
Instance details Defined in Rel8.Type.Ord
DBMin ByteString Source #
Instance details Defined in Rel8.Type.Ord
DBMin Scientific Source #
Instance details Defined in Rel8.Type.Ord
DBMin Text Source #
Instance details Defined in Rel8.Type.Ord
DBMin Text Source #
Instance details Defined in Rel8.Type.Ord
DBMin Day Source #
Instance details Defined in Rel8.Type.Ord
DBMin UTCTime Source #
Instance details Defined in Rel8.Type.Ord
DBMin CalendarDiffTime Source #
Instance details Defined in Rel8.Type.Ord
DBMin LocalTime Source #
Instance details Defined in Rel8.Type.Ord
DBMin TimeOfDay Source #
Instance details Defined in Rel8.Type.Ord
DBMin Char Source #
Instance details Defined in Rel8.Type.Ord
DBMin Double Source #
Instance details Defined in Rel8.Type.Ord
DBMin Float Source #
Instance details Defined in Rel8.Type.Ord
DBMin (CI Text) Source #
Instance details Defined in Rel8.Type.Ord
DBMin (CI Text) Source #
Instance details Defined in Rel8.Type.Ord
(DBComposite a, OrdTable (HKD a Expr)) => DBMin (Composite a) Source #
Instance details Defined in Rel8.Type.Composite
DBEnum a => DBMin (Enum a) Source #
Instance details Defined in Rel8.Type.Enum
Sql DBMin a => DBMin (NonEmpty a) Source #
Instance details Defined in Rel8.Type.Ord
Sql DBMin a => DBMin [a] Source #
Instance details Defined in Rel8.Type.Ord

min :: Sql DBMin a => Expr a -> Aggregate a Source #

Produce an aggregation for Expr a using the max function.

class DBType a => DBSum a Source #

The class of database types that support the sum() aggregation function.

Instances

Instances details

DBSum Int16 Source #
Instance details Defined in Rel8.Type.Sum
DBSum Int32 Source #
Instance details Defined in Rel8.Type.Sum
DBSum Int64 Source #
Instance details Defined in Rel8.Type.Sum
DBSum Scientific Source #
Instance details Defined in Rel8.Type.Sum
DBSum CalendarDiffTime Source #
Instance details Defined in Rel8.Type.Sum
DBSum Double Source #
Instance details Defined in Rel8.Type.Sum
DBSum Float Source #
Instance details Defined in Rel8.Type.Sum

sum :: Sql DBSum a => Expr a -> Aggregate a Source #

Corresponds to sum. Note that in SQL, sum is type changing - for example the sum of integer returns a bigint. Rel8 doesn't support this, and will add explicit casts back to the original input type. This can lead to overflows, and if you anticipate very large sums, you should upcast your input.

sumWhere :: (Sql DBNum a, Sql DBSum a) => Expr Bool -> Expr a -> Aggregate a Source #

Take the sum of all expressions that satisfy a predicate.

avg :: Sql DBSum a => Expr a -> Aggregate a Source #

Corresponds to avg. Note that in SQL, avg is type changing - for example, the avg of integer returns a numeric. Rel8 doesn't support this, and will add explicit casts back to the original input type. If you need a fractional result on an integral column, you should cast your input to Double or Scientific before calling avg.

class DBType a => DBString a Source #

The class of data types that support the string_agg() aggregation function.

Instances

Instances details

DBString ByteString Source #
Instance details Defined in Rel8.Type.String
DBString ByteString Source #
Instance details Defined in Rel8.Type.String
DBString Text Source #
Instance details Defined in Rel8.Type.String
DBString Text Source #
Instance details Defined in Rel8.Type.String
DBString (CI Text) Source #
Instance details Defined in Rel8.Type.String
DBString (CI Text) Source #
Instance details Defined in Rel8.Type.String

stringAgg :: Sql DBString a => Expr db -> Expr a -> Aggregate a Source #

Corresponds to string_agg().

count :: Expr a -> Aggregate Int64 Source #

Count the occurances of a single column. Corresponds to COUNT(a)

countStar :: Aggregate Int64 Source #

Corresponds to COUNT(*).

countDistinct :: Sql DBEq a => Expr a -> Aggregate Int64 Source #

Count the number of distinct occurances of a single column. Corresponds to COUNT(DISTINCT a)

countWhere :: Expr Bool -> Aggregate Int64 Source #

A count of the number of times a given expression is true.

and :: Expr Bool -> Aggregate Bool Source #

Corresponds to bool_and.

or :: Expr Bool -> Aggregate Bool Source #

Corresponds to bool_or.

Ordering

orderBy :: Order a -> Query a -> Query a Source #

Order the rows returned by a query.

data Order a Source #

An ordering expression for a. Primitive orderings are defined with asc and desc, and you can combine Order via its various instances.

A common pattern is to use <> to combine multiple orderings in sequence, and >$< to select individual columns.

Instances

Instances details

Contravariant Order Source #
Instance details Defined in Rel8.Order Methods contramap :: (a' -> a) -> Order a -> Order a' # (>$) :: b -> Order b -> Order a #
Decidable Order Source #
Instance details Defined in Rel8.Order Methods lose :: (a -> Void) -> Order a # choose :: (a -> Either b c) -> Order b -> Order c -> Order a #
Divisible Order Source #
Instance details Defined in Rel8.Order Methods divide :: (a -> (b, c)) -> Order b -> Order c -> Order a # conquer :: Order a #
Monoid (Order a) Source #
Instance details Defined in Rel8.Order Methods mempty :: Order a # mappend :: Order a -> Order a -> Order a # mconcat :: [Order a] -> Order a #
Semigroup (Order a) Source #
Instance details Defined in Rel8.Order Methods (<>) :: Order a -> Order a -> Order a # sconcat :: NonEmpty (Order a) -> Order a # stimes :: Integral b => b -> Order a -> Order a #

asc :: DBOrd a => Order (Expr a) Source #

Sort a column in ascending order.

desc :: DBOrd a => Order (Expr a) Source #

Sort a column in descending order.

nullsFirst :: Order (Expr a) -> Order (Expr (Maybe a)) Source #

Transform an ordering so that null values appear first. This corresponds to NULLS FIRST in SQL.

nullsLast :: Order (Expr a) -> Order (Expr (Maybe a)) Source #

Transform an ordering so that null values appear first. This corresponds to NULLS LAST in SQL.

Window functions

data Window a b Source #

Window is an applicative functor that represents expressions that contain window functions. window can be used to evaluate these expressions over a particular query.

Instances

Instances details

ProductProfunctor Window Source #
Instance details Defined in Rel8.Window Methods purePP :: b -> Window a b # (**) :: Window a (b -> c) -> Window a b -> Window a c # empty :: Window () () # (*!) :: Window a b -> Window a' b' -> Window (a, a') (b, b') #
Profunctor Window Source #
Instance details Defined in Rel8.Window Methods dimap :: (a -> b) -> (c -> d) -> Window b c -> Window a d # lmap :: (a -> b) -> Window b c -> Window a c # rmap :: (b -> c) -> Window a b -> Window a c # (#.) :: forall a b c q. Coercible c b => q b c -> Window a b -> Window a c # (.#) :: forall a b c q. Coercible b a => Window b c -> q a b -> Window a c #
Applicative (Window a) Source #
Instance details Defined in Rel8.Window Methods pure :: a0 -> Window a a0 # (<>) :: Window a (a0 -> b) -> Window a a0 -> Window a b # liftA2 :: (a0 -> b -> c) -> Window a a0 -> Window a b -> Window a c # (>) :: Window a a0 -> Window a b -> Window a b # (<*) :: Window a a0 -> Window a b -> Window a a0 #
Functor (Window a) Source #
Instance details Defined in Rel8.Window Methods fmap :: (a0 -> b) -> Window a a0 -> Window a b # (<$) :: a0 -> Window a b -> Window a a0 #
Apply (Window a) Source #
Instance details Defined in Rel8.Window Methods (<.>) :: Window a (a0 -> b) -> Window a a0 -> Window a b # (.>) :: Window a a0 -> Window a b -> Window a b # (<.) :: Window a a0 -> Window a b -> Window a a0 # liftF2 :: (a0 -> b -> c) -> Window a a0 -> Window a b -> Window a c #

window :: Window a b -> Query a -> Query b Source #

window runs a query composed of expressions containing window functions. window is similar to aggregate, with the main difference being that in a window query, each input row corresponds to one output row, whereas aggregation queries fold the entire input query down into a single row. To put this into a Haskell context, aggregate is to foldl as window is to scanl.

data Partition a Source #

In PostgreSQL, window functions must specify the "window" or "partition" over which they operate. The syntax for this looks like: SUM(salary) OVER (PARTITION BY department). The Rel8 type Partition represents everything that comes after OVER.

Partition is a Monoid, so Windows created with partitionBy and orderWindowBy can be combined using <>.

Instances

Instances details

Contravariant Partition Source #
Instance details Defined in Rel8.Window Methods contramap :: (a' -> a) -> Partition a -> Partition a' # (>$) :: b -> Partition b -> Partition a #
Monoid (Partition a) Source #
Instance details Defined in Rel8.Window Methods mempty :: Partition a # mappend :: Partition a -> Partition a -> Partition a # mconcat :: [Partition a] -> Partition a #
Semigroup (Partition a) Source #
Instance details Defined in Rel8.Window Methods (<>) :: Partition a -> Partition a -> Partition a # sconcat :: NonEmpty (Partition a) -> Partition a # stimes :: Integral b => b -> Partition a -> Partition a #

over :: Window a b -> Partition a -> Window a b infixl 1 Source #

over adds a Partition to a Window expression.

@@cumulative (sum . salary) over partitionBy department <> orderPartitionBy (salary >$< desc)@@

partitionBy :: forall b a. EqTable b => (a -> b) -> Partition a Source #

Restricts a window function to operate only the group of rows that share the same value(s) for the given expression(s).

orderPartitionBy :: Order a -> Partition a Source #

Controls the order in which rows are processed by window functions. This does not need to match the ordering of the overall query.

cumulative :: Aggregates aggregates exprs => (a -> aggregates) -> Window a exprs Source #

cumulative allows the use of aggregation functions in Window expressions. In particular, cumulative sum (when combined with orderPartitionBy) gives a running total, also known as a "cumulative sum", hence the name cumulative.

cumulative_ :: Aggregates aggregates exprs => aggregates -> Window a exprs Source #

A version of cumulative for use with nullary aggregators like countStar.

currentRow :: Window a a Source #

Return every column of the current row of a window query.

rowNumber :: Window a (Expr Int64) Source #

row_number()

rank :: Window a (Expr Int64) Source #

rank()

denseRank :: Window a (Expr Int64) Source #

dense_rank()

percentRank :: Window a (Expr Double) Source #

percent_rank()

cumeDist :: Window a (Expr Double) Source #

cume_dist()

ntile :: Expr Int32 -> Window a (Expr Int32) Source #

ntile(num_buckets)

lag :: Expr Int32 -> Expr a -> Window (Expr a) (Expr a) Source #

lag(value, offset, default)

lead :: Expr Int32 -> Expr a -> Window (Expr a) (Expr a) Source #

lead(value, offset, default)

firstValue :: Window (Expr a) (Expr a) Source #

first_value(value)

lastValue :: Window (Expr a) (Expr a) Source #

last_value(value)

nthValue :: Expr Int32 -> Window (Expr a) (Expr (Nullify a)) Source #

nth_value(value, n)

indexed :: Query a -> Query (Expr Int64, a) Source #

Pair each row of a query with its index within the query.

Bindings

rebind :: Table Expr a => String -> a -> Query a Source #

rebind takes a variable name, some expressions, and binds each of them to a new variable in the SQL. The a returned consists only of these variables. It's essentially a let binding for Postgres expressions.

IO

class (ToExprs exprs a, a ~ FromExprs exprs) => Serializable exprs a | exprs -> a Source #

Serializable witnesses the one-to-one correspondence between the type sql, which contains SQL expressions, and the type haskell, which contains the Haskell decoding of rows containing sql SQL expressions.

Instances

Instances details

(ToExprs exprs a, a ~ FromExprs exprs) => Serializable exprs a Source #
Instance details Defined in Rel8.Table.Serialize
Sql DBType a => Serializable (Expr a) a Source #
Instance details Defined in Rel8.Table.Serialize

class Table Expr exprs => ToExprs exprs a Source #

ToExprs exprs a is evidence that the types exprs and a describe essentially the same type, but exprs is in the Expr context, and a is a normal Haskell type.

Instances

Instances details

(Sql DBType a, x ~ Expr a) => ToExprs x a Source #
Instance details Defined in Rel8.Table.Serialize
(Rel8able t', t' ~ Choose (Algebra t) t, x ~ t' Expr, result ~ Result) => ToExprs x (t result) Source #
Instance details Defined in Rel8.Table.Rel8able
(ToExprs exprs1 a, ToExprs exprs2 b, x ~ EitherTable Expr exprs1 exprs2) => ToExprs x (Either a b) Source #
Instance details Defined in Rel8.Table.Either
(ToExprs exprs1 a, ToExprs exprs2 b, x ~ TheseTable Expr exprs1 exprs2) => ToExprs x (These a b) Source #
Instance details Defined in Rel8.Table.These
(ToExprs exprs1 a, ToExprs exprs2 b, x ~ (exprs1, exprs2)) => ToExprs x (a, b) Source #
Instance details Defined in Rel8.Table.Serialize
(ToExprs exprs1 a, ToExprs exprs2 b, ToExprs exprs3 c, x ~ (exprs1, exprs2, exprs3)) => ToExprs x (a, b, c) Source #
Instance details Defined in Rel8.Table.Serialize
(ToExprs exprs1 a, ToExprs exprs2 b, ToExprs exprs3 c, ToExprs exprs4 d, x ~ (exprs1, exprs2, exprs3, exprs4)) => ToExprs x (a, b, c, d) Source #
Instance details Defined in Rel8.Table.Serialize
(ToExprs exprs1 a, ToExprs exprs2 b, ToExprs exprs3 c, ToExprs exprs4 d, ToExprs exprs5 e, x ~ (exprs1, exprs2, exprs3, exprs4, exprs5)) => ToExprs x (a, b, c, d, e) Source #
Instance details Defined in Rel8.Table.Serialize
(ToExprs exprs1 a, ToExprs exprs2 b, ToExprs exprs3 c, ToExprs exprs4 d, ToExprs exprs5 e, ToExprs exprs6 f, x ~ (exprs1, exprs2, exprs3, exprs4, exprs5, exprs6)) => ToExprs x (a, b, c, d, e, f) Source #
Instance details Defined in Rel8.Table.Serialize
(ToExprs exprs1 a, ToExprs exprs2 b, ToExprs exprs3 c, ToExprs exprs4 d, ToExprs exprs5 e, ToExprs exprs6 f, ToExprs exprs7 g, x ~ (exprs1, exprs2, exprs3, exprs4, exprs5, exprs6, exprs7)) => ToExprs x (a, b, c, d, e, f, g) Source #
Instance details Defined in Rel8.Table.Serialize
(Sql DBType a, NotNull a, x ~ NonEmpty a) => ToExprs (Expr x) (NonEmpty a) Source #
Instance details Defined in Rel8.Table.Serialize
(Sql DBType a, NotNull a, x ~ Maybe a) => ToExprs (Expr x) (Maybe a) Source #
Instance details Defined in Rel8.Table.Serialize
(Sql DBType a, x ~ [a]) => ToExprs (Expr x) [a] Source #
Instance details Defined in Rel8.Table.Serialize
(ToExprs exprs a, context ~ Expr) => ToExprs (ListTable context exprs) [a] Source #
Instance details Defined in Rel8.Table.List
(ToExprs exprs a, context ~ Expr) => ToExprs (MaybeTable context exprs) (Maybe a) Source #
Instance details Defined in Rel8.Table.Maybe
(ToExprs exprs a, context ~ Expr) => ToExprs (NonEmptyTable context exprs) (NonEmpty a) Source #
Instance details Defined in Rel8.Table.NonEmpty
(ToExprs exprs a, context ~ Expr) => ToExprs (NullTable context exprs) (Maybe a) Source #
Instance details Defined in Rel8.Table.Null

type Result = Identity Source #

The Result context is the context used for decoded query results.

When a query is executed against a PostgreSQL database, Rel8 parses the returned rows, decoding each row into the Result context.

Running statements

To run queries and otherwise interact with a PostgreSQL database, Rel8 provides select, insert, update and delete functions. Note that insert, update and delete will generally need the DuplicateRecordFields language extension enabled.

`SELECT`

select :: forall exprs a. Serializable exprs a => Query exprs -> Statement () [a] Source #

Run a SELECT statement, returning all rows.

`INSERT`

data Insert a where Source #

The constituent parts of a SQL INSERT statement.

Constructors

Insert

Fields

:: Selects names exprs
=> { into :: TableSchema names
Which table to insert into.
, rows :: Query exprs
The rows to insert. This can be an arbitrary query — use values insert a static list of rows.
, onConflict :: OnConflict names
What to do if the inserted rows conflict with data already in the table.
, returning :: Returning names a
What information to return on completion.
} -> Insert a

data OnConflict names Source #

OnConflict represents the ON CONFLICT clause of an INSERT statement. This specifies what ought to happen when one or more of the rows proposed for insertion conflict with an existing row in the table.

Constructors

Abort	Abort the transaction if there are conflicting rows (Postgres' default)
DoNothing	ON CONFLICT DO NOTHING
DoUpdate (Upsert names)	ON CONFLICT DO UPDATE

data Upsert names where Source #

The ON CONFLICT (...) DO UPDATE clause of an INSERT statement, also known as "upsert".

When an existing row conflicts with a row proposed for insertion, ON CONFLICT DO UPDATE allows you to instead update this existing row. The conflicting row proposed for insertion is then "excluded", but its values can still be referenced from the SET and WHERE clauses of the UPDATE statement.

Upsert in Postgres requires an explicit set of "conflict targets" — the set of columns comprising the UNIQUE index from conflicts with which we would like to recover.

Constructors

Upsert
Fields :: (Selects names exprs, Projecting names index, excluded ~ exprs) => { index :: Projection names index The set of conflict targets, projected from the set of columns for the whole table , set :: excluded -> exprs -> exprs How to update each selected row. , updateWhere :: excluded -> exprs -> Expr Bool Which rows to select for update. } -> Upsert names

insert :: Insert a -> Statement () a Source #

Run an Insert statement.

unsafeDefault :: Expr a Source #

Corresponds to the SQL DEFAULT expression.

This Expr is unsafe for numerous reasons, and should be used with care:

This Expr only makes sense in an INSERT or UPDATE statement.
Rel8 is not able to verify that a particular column actually has a DEFAULT value. Trying to use unsafeDefault where there is no default will cause a runtime crash
DEFAULT values can not be transformed. For example, the innocuous Rel8 code unsafeDefault + 1 will crash, despite type checking.

Given all these caveats, we suggest avoiding the use of default values where possible, instead being explicit. A common scenario where default values are used is with auto-incrementing identifier columns. In this case, we suggest using nextval instead.

showInsert :: Insert a -> String Source #

Convert an Insert to a String containing an INSERT statement.

`DELETE`

data Delete a where Source #

The constituent parts of a DELETE statement.

Constructors

Delete

Fields

:: Selects names exprs
=> { from :: TableSchema names
Which table to delete from.
, using :: Query using
USING clause — this can be used to join against other tables, and its results can be referenced in the WHERE clause
, deleteWhere :: using -> exprs -> Expr Bool
Which rows should be selected for deletion.
, returning :: Returning names a
What to return from the DELETE statement.
} -> Delete a

delete :: Delete a -> Statement () a Source #

Run a Delete statement.

showDelete :: Delete a -> String Source #

Convert a Delete to a String containing a DELETE statement.

`UPDATE`

data Update a where Source #

The constituent parts of an UPDATE statement.

Constructors

Update

Fields

:: Selects names exprs
=> { target :: TableSchema names
Which table to update.
, from :: Query from
FROM clause — this can be used to join against other tables, and its results can be referenced in the SET and WHERE clauses.
, set :: from -> exprs -> exprs
How to update each selected row.
, updateWhere :: from -> exprs -> Expr Bool
Which rows to select for update.
, returning :: Returning names a
What to return from the UPDATE statement.
} -> Update a

update :: Update a -> Statement () a Source #

Run an UPDATE statement.

showUpdate :: Update a -> String Source #

Convert an Update to a String containing an UPDATE statement.

`.. RETURNING`

data Returning names a where Source #

Insert, Update and Delete all support returning either the number of rows affected, or the actual rows modified.

Constructors

NumberOfRowsAffected :: Returning names Int64	Return the number of rows affected.
Projection :: (Selects names exprs, Serializable returning a) => (exprs -> returning) -> Returning names [a]	`Projection` allows you to project out of the affected rows, which can be useful if you want to log exactly which rows were deleted, or to view a generated id (for example, if using a column with an autoincrementing counter via `nextval`).

Instances

Instances details

Applicative (Returning names) Source #
Instance details Defined in Rel8.Statement.Returning Methods pure :: a -> Returning names a # (<>) :: Returning names (a -> b) -> Returning names a -> Returning names b # liftA2 :: (a -> b -> c) -> Returning names a -> Returning names b -> Returning names c # (>) :: Returning names a -> Returning names b -> Returning names b # (<*) :: Returning names a -> Returning names b -> Returning names a #
Functor (Returning names) Source #
Instance details Defined in Rel8.Statement.Returning Methods fmap :: (a -> b) -> Returning names a -> Returning names b # (<$) :: a -> Returning names b -> Returning names a #
Apply (Returning names) Source #
Instance details Defined in Rel8.Statement.Returning Methods (<.>) :: Returning names (a -> b) -> Returning names a -> Returning names b # (.>) :: Returning names a -> Returning names b -> Returning names b # (<.) :: Returning names a -> Returning names b -> Returning names a # liftF2 :: (a -> b -> c) -> Returning names a -> Returning names b -> Returning names c #

`CREATE VIEW`

createView :: Selects names exprs => TableSchema names -> Query exprs -> Statement () () Source #

Given a TableSchema and Query, createView runs a CREATE VIEW statement that will save the given query as a view. This can be useful if you want to share Rel8 queries with other applications.

createOrReplaceView :: Selects names exprs => TableSchema names -> Query exprs -> Statement () () Source #

Given a TableSchema and Query, createOrReplaceView runs a CREATE OR REPLACE VIEW statement that will save the given query as a view, replacing the current view definition if it exists and adheres to the restrictions in place for replacing a view in PostgreSQL.

Sequences

nextval :: String -> Expr Int64 Source #

See https://www.postgresql.org/docs/current/functions-sequence.html

evaluate :: Table Expr a => a -> Query a Source #

evaluate takes expressions that could potentially have side effects and "runs" them in the Query monad. The returned expressions have no side effects and can safely be reused.

AltTable Query Source #	`<\|>:` = `unionAll`.
Instance details Defined in Rel8.Query Methods (<\|>:) :: Table Expr a => Query a -> Query a -> Query a Source #
context ~ Expr => AltTable (ListTable context) Source #
Instance details Defined in Rel8.Table.List Methods (<\|>:) :: Table Expr a => ListTable context a -> ListTable context a -> ListTable context a Source #
context ~ Expr => AltTable (MaybeTable context) Source #
Instance details Defined in Rel8.Table.Maybe Methods (<\|>:) :: Table Expr a => MaybeTable context a -> MaybeTable context a -> MaybeTable context a Source #
context ~ Expr => AltTable (NonEmptyTable context) Source #
Instance details Defined in Rel8.Table.NonEmpty Methods (<\|>:) :: Table Expr a => NonEmptyTable context a -> NonEmptyTable context a -> NonEmptyTable context a Source #
context ~ Expr => AltTable (NullTable context) Source #
Instance details Defined in Rel8.Table.Null Methods (<\|>:) :: Table Expr a => NullTable context a -> NullTable context a -> NullTable context a Source #
EqTable k => AltTable (Tabulation k) Source #	If `Tabulation k a` is `Map k (NonEmpty a)`, then `(\|:)` is `unionWith (<>)`.
Instance details Defined in Rel8.Tabulate Methods (<\|>:) :: Table Expr a => Tabulation k a -> Tabulation k a -> Tabulation k a Source #

Database types

DBType

Instances

Deriving-via helpers

JSONEncoded

Instances

Instances

ReadShow

Instances

Generic

Instances

Instances

Instances

TypeInformation

The DBType hierarchy

Instances

Instances

Instances

Instances

Instances

Instances

Tables and higher-kinded tables

Instances

Instances

Instances

Instances

Instances

Instances

Instances

MaybeTable

Instances

EitherTable

Instances

TheseTable

Instances

ListTable

Instances

NonEmptyTable

Instances

NullTable

Instances

Algebraic data types / sum types

Naming of ADTs

Instances

Instances

Deconstruction of ADTs

Construction of ADTs

Other ADT operations

Miscellaneous notes

HKD

Instances

Instances

Table schemas

Instances

Instances

Expressions

Instances

Instances

null

Instances

Instances

Instances

Boolean operations

Instances

Ordering

Instances

Functions

Instances

Queries

Instances

Projection

Instances

Instances

Instances

Instances

Selecting rows

Instances

Filtering

LIMIT/OFFSET

UNION

`DBType`

`JSONEncoded`

`ReadShow`

`TypeInformation`

The `DBType` hierarchy

`MaybeTable`

`EitherTable`

`TheseTable`

`ListTable`

`NonEmptyTable`

`NullTable`

`HKD`

`null`

`LIMIT`/`OFFSET`

`UNION`

`INTERSECT`

`EXCEPT`

`EXISTS`

`SELECT`

`INSERT`

`DELETE`

`UPDATE`

`.. RETURNING`

`CREATE VIEW`