Copyright | 2014-2017 Kei Hibino |
---|---|

License | BSD3 |

Maintainer | ex8k.hibino@gmail.com |

Stability | experimental |

Portability | unknown |

Safe Haskell | None |

Language | Haskell2010 |

This module is documentation module for relational-record. The project page of relational-record is http://khibino.github.io/haskell-relational-record/ .

- query :: (MonadQualify ConfigureQuery m, MonadQuery m) => Relation () r -> m (Projection Flat r)
- queryMaybe :: (MonadQualify ConfigureQuery m, MonadQuery m) => Relation () r -> m (Projection Flat (Maybe r))
- on :: MonadQuery m => Projection Flat (Maybe Bool) -> m ()
- wheres :: MonadRestrict Flat m => Projection Flat (Maybe Bool) -> m ()
- groupBy :: MonadAggregate m => forall r. Projection Flat r -> m (Projection Aggregated r)
- having :: MonadRestrict Aggregated m => Projection Aggregated (Maybe Bool) -> m ()
- distinct :: MonadQuery m => m ()
- all' :: MonadQuery m => m ()
- (<-#) :: Monad m => AssignTarget r v -> Projection Flat v -> Assignings r m ()
- inner :: Relation () a -> Relation () b -> [JoinRestriction a b] -> Relation () (a, b)
- left :: Relation () a -> Relation () b -> [JoinRestriction a (Maybe b)] -> Relation () (a, Maybe b)
- right :: Relation () a -> Relation () b -> [JoinRestriction (Maybe a) b] -> Relation () (Maybe a, b)
- full :: Relation () a -> Relation () b -> [JoinRestriction (Maybe a) (Maybe b)] -> Relation () (Maybe a, Maybe b)
- on' :: ([JoinRestriction a b] -> Relation pc (a, b)) -> [JoinRestriction a b] -> Relation pc (a, b)
- type JoinRestriction a b = Projection Flat a -> Projection Flat b -> Projection Flat (Maybe Bool)
- data Relation p r :: * -> * -> *
- relation :: QuerySimple (Projection Flat r) -> Relation () r
- aggregateRelation :: QueryAggregate (Projection Aggregated r) -> Relation () r
- data UpdateTarget p r :: * -> * -> *
- updateTarget :: AssignStatement r () -> UpdateTarget () r
- data Restriction p r :: * -> * -> *
- restriction :: RestrictedStatement r () -> Restriction () r
- data Projection c t :: * -> * -> *
- data Flat :: *
- data Aggregated :: *
- data Exists :: *
- data OverWindow :: *
- data Pi r0 r1 :: * -> * -> *
- (!) :: Projection c a -> Pi a b -> Projection c b
- (<.>) :: Pi a b -> Pi b c -> Pi a c
- class ShowConstantTermsSQL a
- value :: (ShowConstantTermsSQL t, OperatorProjectable p) => t -> p t
- values :: (ShowConstantTermsSQL t, OperatorProjectable p) => [t] -> ListProjection p t
- (.=.) :: (OperatorProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)
- (.<.) :: (OperatorProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)
- (.<=.) :: (OperatorProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)
- (.>.) :: (OperatorProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)
- (.>=.) :: (OperatorProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)
- (.<>.) :: (OperatorProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool)
- and' :: (OperatorProjectable p, ProjectableShowSql p) => p (Maybe Bool) -> p (Maybe Bool) -> p (Maybe Bool)
- or' :: (OperatorProjectable p, ProjectableShowSql p) => p (Maybe Bool) -> p (Maybe Bool) -> p (Maybe Bool)
- in' :: (OperatorProjectable p, ProjectableShowSql p) => p t -> ListProjection p t -> p (Maybe Bool)
- (.||.) :: (OperatorProjectable p, ProjectableShowSql p, IsString a) => p a -> p a -> p a
- like :: (OperatorProjectable p, ProjectableShowSql p, IsString a, ShowConstantTermsSQL a) => p a -> a -> p (Maybe Bool)
- like' :: (OperatorProjectable p, ProjectableShowSql p, IsString a) => p a -> p a -> p (Maybe Bool)
- (.+.) :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p a -> p a -> p a
- (.-.) :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p a -> p a -> p a
- (.*.) :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p a -> p a -> p a
- (./.) :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p a -> p a -> p a
- isNothing :: (OperatorProjectable (Projection c), ProjectableShowSql (Projection c), HasColumnConstraint NotNull r) => Projection c (Maybe r) -> Projection c (Maybe Bool)
- isJust :: (OperatorProjectable (Projection c), ProjectableShowSql (Projection c), HasColumnConstraint NotNull r) => Projection c (Maybe r) -> Projection c (Maybe Bool)
- fromMaybe :: (OperatorProjectable (Projection c), ProjectableShowSql (Projection c), HasColumnConstraint NotNull r) => Projection c r -> Projection c (Maybe r) -> Projection c r
- not' :: (OperatorProjectable p, ProjectableShowSql p) => p (Maybe Bool) -> p (Maybe Bool)
- exists :: (OperatorProjectable p, ProjectableShowSql p) => ListProjection (Projection Exists) r -> p (Maybe Bool)
- negate' :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p a -> p a
- fromIntegral' :: (SqlProjectable p, ProjectableShowSql p, Integral a, Num b) => p a -> p b
- showNum :: (SqlProjectable p, ProjectableShowSql p, Num a, IsString b) => p a -> p b
- casesOrElse :: (OperatorProjectable p, ProjectableShowSql p) => [(p (Maybe Bool), p a)] -> p a -> p a
- case' :: (OperatorProjectable p, ProjectableShowSql p) => p a -> [(p a, p b)] -> p b -> p b
- count :: (Integral b, AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat a -> p ac b
- sum' :: (Num a, AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat a -> p ac (Maybe a)
- avg :: (Num a, Fractional b, AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat a -> p ac (Maybe b)
- max' :: (Ord a, AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat a -> p ac (Maybe a)
- min' :: (Ord a, AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat a -> p ac (Maybe a)
- every :: (AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat (Maybe Bool) -> p ac (Maybe Bool)
- any' :: (AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat (Maybe Bool) -> p ac (Maybe Bool)
- some' :: (AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat (Maybe Bool) -> p ac (Maybe Bool)
- over :: SqlProjectable (Projection c) => Projection OverWindow a -> Window c () -> Projection c a
- rank :: Integral a => Projection OverWindow a
- denseRank :: Integral a => Projection OverWindow a
- rowNumber :: Integral a => Projection OverWindow a
- percentRank :: Projection OverWindow Double
- cumeDist :: Projection OverWindow Double
- union :: Relation () a -> Relation () a -> Relation () a
- except :: Relation () a -> Relation () a -> Relation () a
- intersect :: Relation () a -> Relation () a -> Relation () a
- just :: ProjectableMaybe p => forall a. p a -> p (Maybe a)
- flattenMaybe :: ProjectableMaybe p => forall a. p (Maybe (Maybe a)) -> p (Maybe a)
- (?!) :: Projection c (Maybe a) -> Pi a b -> Projection c (Maybe b)
- (?!?) :: Projection c (Maybe a) -> Pi a (Maybe b) -> Projection c (Maybe b)
- (<?.>) :: Pi a (Maybe b) -> Pi b c -> Pi a (Maybe c)
- (<?.?>) :: Pi a (Maybe b) -> Pi b (Maybe c) -> Pi a (Maybe c)
- (?+?) :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p (Maybe a) -> p (Maybe a) -> p (Maybe a)
- negateMaybe :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p (Maybe a) -> p (Maybe a)
- sumMaybe :: (Num a, AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat (Maybe a) -> p ac (Maybe a)
- placeholder :: (PersistableWidth t, SqlProjectable p, Monad m) => (p t -> m a) -> m (PlaceHolders t, a)
- query' :: MonadQuery m => forall p r. Relation p r -> m (PlaceHolders p, Projection Flat r)
- left' :: Relation pa a -> Relation pb b -> [JoinRestriction a (Maybe b)] -> Relation (pa, pb) (a, Maybe b)
- relation' :: SimpleQuery p r -> Relation p r
- updateTarget' :: AssignStatement r (PlaceHolders p) -> UpdateTarget p r
- restriction' :: RestrictedStatement r (PlaceHolders p) -> Restriction p r
- union' :: Relation p a -> Relation q a -> Relation (p, q) a
- class ProductConstructor r
- class ProjectableFunctor p where
- class ProjectableFunctor p => ProjectableApplicative p where
- (><) :: ProjectableApplicative p => p a -> p b -> p (a, b)
- relationalQuery :: Relation p r -> Query p r
- typedInsert :: Table r -> Pi r r' -> Insert r'
- typedInsertQuery :: Table r -> Pi r r' -> Relation p r' -> InsertQuery p
- typedUpdate :: Table r -> UpdateTarget p r -> Update p
- typedDelete :: Table r -> Restriction p r -> Delete p
- typedKeyUpdate :: Table a -> Pi a p -> KeyUpdate p a
- derivedInsert :: TableDerivable r => Pi r r' -> Insert r'
- derivedInsertQuery :: TableDerivable r => Pi r r' -> Relation p r' -> InsertQuery p
- derivedUpdate :: TableDerivable r => AssignStatement r (PlaceHolders p) -> Update p
- derivedDelete :: TableDerivable r => RestrictedStatement r (PlaceHolders p) -> Delete p
- class FromSql q a
- class ToSql q a
- data RecordFromSql q a :: * -> * -> *
- data RecordToSql q a :: * -> * -> *
- prepareNoFetch :: (UntypeableNoFetch s, IConnection conn) => conn -> s p -> IO (PreparedStatement p ())
- bind :: ToSql SqlValue p => PreparedStatement p a -> p -> BoundStatement a
- execute :: BoundStatement a -> IO (ExecutedStatement a)
- executeNoFetch :: BoundStatement () -> IO Integer
- prepareQuery :: IConnection conn => conn -> Query p a -> IO (PreparedQuery p a)
- fetch :: FromSql SqlValue a => ExecutedStatement a -> IO (Maybe a)
- runQuery :: (IConnection conn, ToSql SqlValue p, FromSql SqlValue a) => conn -> Query p a -> p -> IO [a]
- runQuery' :: (IConnection conn, ToSql SqlValue p, FromSql SqlValue a) => conn -> Query p a -> p -> IO [a]
- prepareInsert :: IConnection conn => conn -> Insert a -> IO (PreparedInsert a)
- runInsert :: (IConnection conn, ToSql SqlValue a) => conn -> Insert a -> a -> IO Integer
- prepareInsertQuery :: IConnection conn => conn -> InsertQuery p -> IO (PreparedInsertQuery p)
- runInsertQuery :: (IConnection conn, ToSql SqlValue p) => conn -> InsertQuery p -> p -> IO Integer
- prepareUpdate :: IConnection conn => conn -> Update p -> IO (PreparedUpdate p)
- runUpdate :: (IConnection conn, ToSql SqlValue p) => conn -> Update p -> p -> IO Integer
- prepareDelete :: IConnection conn => conn -> Delete p -> IO (PreparedDelete p)
- runDelete :: (IConnection conn, ToSql SqlValue p) => conn -> Delete p -> p -> IO Integer
- prepareKeyUpdate :: IConnection conn => conn -> KeyUpdate p a -> IO (PreparedKeyUpdate p a)
- bindKeyUpdate :: ToSql SqlValue a => PreparedKeyUpdate p a -> a -> BoundStatement ()
- runKeyUpdate :: (IConnection conn, ToSql SqlValue a) => conn -> KeyUpdate p a -> a -> IO Integer

# Concepts

User interface of Relational Record has main two part of modules.

`Database.Relational.Query`

- Relational Query Building DSL
`Database.Record and Database.HDBC.Record`

- Database Operation Actions

# Relational Query Building DSL

Relational Query (Database.Relational.Query) module defines Typed DSL to build complex SQL query.

## Monadic Query Context Building

On building query, query structures can be accumulated in monadic context.

### Monadic Operators

Some operators are defined to build query structures in monadic context.

`query`

and `queryMaybe`

operators grow query product of monadic context like join operation of SQL.
`on`

operator appends a new condition into recent join product condition.

`groupBy`

operator aggregates flat projection value, and can be used only in `MonadAggregate`

context.

`wheres`

and `having`

operators appends a new condition into whole query condition.
`having`

only accepts aggregated projection value, and can be used only in `MonadRestrict`

`Aggregated`

context.

`distinct`

operator and `all'`

operator specify SELECT DISTINCT or SELECT ALL, the last specified in monad is used.

`<-#`

operator assigns update target column and projection value to build update statement structure.

query :: (MonadQualify ConfigureQuery m, MonadQuery m) => Relation () r -> m (Projection Flat r) #

Join sub-query. Query result is not `Maybe`

.

queryMaybe :: (MonadQualify ConfigureQuery m, MonadQuery m) => Relation () r -> m (Projection Flat (Maybe r)) #

Join sub-query. Query result is `Maybe`

.
The combinations of `query`

and `queryMaybe`

express
inner joins, left outer joins, right outer joins, and full outer joins.
Here is an example of a right outer join:

outerJoin = relation $ do e <- queryMaybe employee d <- query department on $ e ?! E.deptId' .=. just (d ! D.deptId') return $ (,) |$| e |*| d

on :: MonadQuery m => Projection Flat (Maybe Bool) -> m () #

Add restriction to last join. Projection type version.

wheres :: MonadRestrict Flat m => Projection Flat (Maybe Bool) -> m () #

Add restriction to this not aggregated query.

groupBy :: MonadAggregate m => forall r. Projection Flat r -> m (Projection Aggregated r) #

Add *GROUP BY* term into context and get aggregated projection.

having :: MonadRestrict Aggregated m => Projection Aggregated (Maybe Bool) -> m () #

Add restriction to this aggregated query. Aggregated Projection type version.

distinct :: MonadQuery m => m () #

Specify DISTINCT attribute to query context.

all' :: MonadQuery m => m () #

Specify ALL attribute to query context.

(<-#) :: Monad m => AssignTarget r v -> Projection Flat v -> Assignings r m () infix 4 #

Add and assginment.

### Direct Join Operators

Not monadic style join is supported by some direct join operators.

`inner`

, `left`

, `right`

, `full`

operators can construct join products directly like SQL.
`inner`

operator is INNER JOIN of SQL, `left`

operator is LEFT OUTER JOIN of SQL, and so on.
`on'`

operator specifies condition of join product.
`JoinRestriction`

is the type of lambda form which expresses condition of join product.

:: Relation () a | Left query to join |

-> Relation () b | Right query to join |

-> [JoinRestriction a b] | Join restrictions |

-> Relation () (a, b) | Result joined relation |

Direct inner join.

:: Relation () a | Left query to join |

-> Relation () b | Right query to join |

-> [JoinRestriction a (Maybe b)] | Join restrictions |

-> Relation () (a, Maybe b) | Result joined relation |

Direct left outer join.

:: Relation () a | Left query to join |

-> Relation () b | Right query to join |

-> [JoinRestriction (Maybe a) b] | Join restrictions |

-> Relation () (Maybe a, b) | Result joined relation |

Direct right outer join.

:: Relation () a | Left query to join |

-> Relation () b | Right query to join |

-> [JoinRestriction (Maybe a) (Maybe b)] | Join restrictions |

-> Relation () (Maybe a, Maybe b) | Result joined relation |

Direct full outer join.

on' :: ([JoinRestriction a b] -> Relation pc (a, b)) -> [JoinRestriction a b] -> Relation pc (a, b) infixl 8 #

Apply restriction for direct join style.

type JoinRestriction a b = Projection Flat a -> Projection Flat b -> Projection Flat (Maybe Bool) #

### Finalize Context

Several operators are defined to make `Relation`

type with finalizing query monadic context.

`relation`

operator finalizes flat (not aggregated) query monadic context,
and `aggregateRelation`

operator finalizes aggregated query monadic context.
Both operator convert monadic context into `Relation`

type,
and finalized `Relation`

can be reused as joining and sub-querying in another queries.

`updateTarget`

operator finalize monadic context into `UpdateTarget`

type
which can be used as update statement.

`restriction`

operator finalize monadic context into `Restriction`

type
which can be used as delete statement.

data Relation p r :: * -> * -> * #

Relation type with place-holder parameter `p`

and query result type `r`

.

relation :: QuerySimple (Projection Flat r) -> Relation () r #

Finalize `QuerySimple`

monad and generate `Relation`

.

aggregateRelation :: QueryAggregate (Projection Aggregated r) -> Relation () r #

Finalize `QueryAggregate`

monad and geneate `Relation`

.

data UpdateTarget p r :: * -> * -> * #

UpdateTarget type with place-holder parameter `p`

and projection record type `r`

.

TableDerivable r => Show (UpdateTarget p r) | |

updateTarget :: AssignStatement r () -> UpdateTarget () r #

Finalize `Target`

monad and generate `UpdateTarget`

.

data Restriction p r :: * -> * -> * #

Restriction type with place-holder parameter `p`

and projection record type `r`

.

TableDerivable r => Show (Restriction p r) | Show where clause. |

restriction :: RestrictedStatement r () -> Restriction () r #

Finalize `Restrict`

monad and generate `Restriction`

.

## Projection

SQL expression can be projected to Haskell phantom type in this DSL.

### Projection Type

`Projection`

*c* *t* is SQL value type projection to Haskell type with context type *c* correspond Haskell type *t*.

`Flat`

is not aggregated query context type,
`Aggregated`

is aggregated query context type,
`OverWindow`

is window function context type, and so on.

Module Database.Relational.Query.Context contains documentation of other context types.

data Projection c t :: * -> * -> * #

Phantom typed projection. Projected into Haskell record type `t`

.

OperatorProjectable (Projection Flat) | |

OperatorProjectable (Projection Aggregated) | |

SqlProjectable (Projection Flat) | Unsafely make |

SqlProjectable (Projection Aggregated) | Unsafely make |

SqlProjectable (Projection OverWindow) | Unsafely make |

ProjectableShowSql (Projection c) | Unsafely get SQL term from |

ProjectableMaybe (Projection c) | Control phantom |

Show (Projection c t) | |

Type tag for flat (not-aggregated) query

OperatorProjectable (Projection Flat) | |

SqlProjectable (Projection Flat) | Unsafely make |

data Aggregated :: * #

Type tag for aggregated query

AggregatedContext Aggregated | |

OperatorProjectable (Projection Aggregated) | |

SqlProjectable (Projection Aggregated) | Unsafely make |

data OverWindow :: * #

Type tag for window function building

AggregatedContext OverWindow | |

SqlProjectable (Projection OverWindow) | Unsafely make |

### Projection Path

`!`

operator is projected value selector using projection path type `Pi`

*r0* *r1*.
`Pi`

*r0* *r1* is projection path type selecting column type *r1* from record type *r0*.
`<.>`

operator makes composed projection path from two projection paths.

data Pi r0 r1 :: * -> * -> * #

Projection path from type `r0`

into type `r1`

.
This type also indicate key object which type is `r1`

for record type `r0`

.

ProjectableFunctor (Pi a) | Compose seed of projection path |

ProjectableApplicative (Pi a) | Compose projection path |

:: Projection c a | Source projection |

-> Pi a b | Projection path |

-> Projection c b | Narrower projected object |

Get narrower projection along with projection path.

### Projection Operators

Some operators are defined to calculate projected values.

For example,
`value`

operator projects from Haskell value into `Projection`

corresponding SQL row value,
which projection is implicitly specified by `ShowConstantTermsSQL`

class.
Generic programming with default signature is available to define instances of `ShowConstantTermsSQL`

.

`values`

operator projects from Haskell list value into `ListProjection`

, corresponding SQL set value,
`.=.`

operator is equal compare operation of projected value correspond to SQL =,
`.+.`

operator is plus operation of projected value correspond to SQL +, and so on.

Module Database.Relational.Query.Projectable contains documentation of other projection operators.

class ShowConstantTermsSQL a #

Interface for constant SQL term list.

value :: (ShowConstantTermsSQL t, OperatorProjectable p) => t -> p t #

Generate polymorphic projection of SQL constant values from Haskell value.

values :: (ShowConstantTermsSQL t, OperatorProjectable p) => [t] -> ListProjection p t #

Polymorphic proejction of SQL set value from Haskell list.

(.=.) :: (OperatorProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool) infix 4 #

Compare operator corresponding SQL *=* .

(.<.) :: (OperatorProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool) infix 4 #

Compare operator corresponding SQL *<* .

(.<=.) :: (OperatorProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool) infix 4 #

Compare operator corresponding SQL *<=* .

(.>.) :: (OperatorProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool) infix 4 #

Compare operator corresponding SQL *>* .

(.>=.) :: (OperatorProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool) infix 4 #

Compare operator corresponding SQL *>=* .

(.<>.) :: (OperatorProjectable p, ProjectableShowSql p) => p ft -> p ft -> p (Maybe Bool) infix 4 #

Compare operator corresponding SQL *<>* .

and' :: (OperatorProjectable p, ProjectableShowSql p) => p (Maybe Bool) -> p (Maybe Bool) -> p (Maybe Bool) infixr 3 #

Logical operator corresponding SQL *AND* .

or' :: (OperatorProjectable p, ProjectableShowSql p) => p (Maybe Bool) -> p (Maybe Bool) -> p (Maybe Bool) infixr 2 #

Logical operator corresponding SQL *OR* .

in' :: (OperatorProjectable p, ProjectableShowSql p) => p t -> ListProjection p t -> p (Maybe Bool) infix 4 #

Binary operator corresponding SQL *IN* .

(.||.) :: (OperatorProjectable p, ProjectableShowSql p, IsString a) => p a -> p a -> p a infixl 5 #

Concatinate operator corresponding SQL *||* .

like :: (OperatorProjectable p, ProjectableShowSql p, IsString a, ShowConstantTermsSQL a) => p a -> a -> p (Maybe Bool) infix 4 #

String-compare operator corresponding SQL *LIKE* .

like' :: (OperatorProjectable p, ProjectableShowSql p, IsString a) => p a -> p a -> p (Maybe Bool) infix 4 #

String-compare operator corresponding SQL *LIKE* .

(.+.) :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p a -> p a -> p a infixl 6 #

Number operator corresponding SQL *+* .

(.-.) :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p a -> p a -> p a infixl 6 #

Number operator corresponding SQL *-* .

(.*.) :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p a -> p a -> p a infixl 7 #

Number operator corresponding SQL *** .

(./.) :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p a -> p a -> p a infixl 7 #

Number operator corresponding SQL /// .

isNothing :: (OperatorProjectable (Projection c), ProjectableShowSql (Projection c), HasColumnConstraint NotNull r) => Projection c (Maybe r) -> Projection c (Maybe Bool) #

Operator corresponding SQL *IS NULL* , and extended against record types.

isJust :: (OperatorProjectable (Projection c), ProjectableShowSql (Projection c), HasColumnConstraint NotNull r) => Projection c (Maybe r) -> Projection c (Maybe Bool) #

Operator corresponding SQL *NOT (... IS NULL)* , and extended against record type.

fromMaybe :: (OperatorProjectable (Projection c), ProjectableShowSql (Projection c), HasColumnConstraint NotNull r) => Projection c r -> Projection c (Maybe r) -> Projection c r #

Operator from maybe type using record extended `isNull`

.

not' :: (OperatorProjectable p, ProjectableShowSql p) => p (Maybe Bool) -> p (Maybe Bool) #

Logical operator corresponding SQL *NOT* .

exists :: (OperatorProjectable p, ProjectableShowSql p) => ListProjection (Projection Exists) r -> p (Maybe Bool) #

Logical operator corresponding SQL *EXISTS* .

negate' :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p a -> p a #

Number negate uni-operator corresponding SQL *-*.

fromIntegral' :: (SqlProjectable p, ProjectableShowSql p, Integral a, Num b) => p a -> p b #

Number fromIntegral uni-operator.

showNum :: (SqlProjectable p, ProjectableShowSql p, Num a, IsString b) => p a -> p b #

Unsafely show number into string-like type in projections.

:: (OperatorProjectable p, ProjectableShowSql p) | |

=> [(p (Maybe Bool), p a)] | Each when clauses |

-> p a | Else result projection |

-> p a | Result projection |

Same as `caseSearch`

, but you can write like list `casesOrElse`

clause.

:: (OperatorProjectable p, ProjectableShowSql p) | |

=> p a | Projection value to match |

-> [(p a, p b)] | Each when clauses |

-> p b | Else result projection |

-> p b | Result projection |

Simple case operator correnponding SQL simple *CASE*.
Like, *CASE x WHEN v THEN a WHEN w THEN b ... ELSE c END*

## Aggregate and Window Functions

Typed aggregate function operators are defined. Aggregated value types is distinguished with Flat value types.

For example,
`sum'`

operator is aggregate function of projected flat (not aggregated) value
correspond to SQL SUM(...),
`rank`

operator is window function of projected value correspond to SQL RANK(), and so on.

To convert window function result into normal projection, use the `over`

operator with built `Window`

monad.

Module Database.Relational.Query.Projectable contains documentation of other aggregate function operators and window function operators.

count :: (Integral b, AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat a -> p ac b #

Aggregation function COUNT.

sum' :: (Num a, AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat a -> p ac (Maybe a) #

Aggregation function SUM.

avg :: (Num a, Fractional b, AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat a -> p ac (Maybe b) #

Aggregation function AVG.

max' :: (Ord a, AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat a -> p ac (Maybe a) #

Aggregation function MAX.

min' :: (Ord a, AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat a -> p ac (Maybe a) #

Aggregation function MIN.

every :: (AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat (Maybe Bool) -> p ac (Maybe Bool) #

Aggregation function EVERY.

any' :: (AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat (Maybe Bool) -> p ac (Maybe Bool) #

Aggregation function ANY.

some' :: (AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat (Maybe Bool) -> p ac (Maybe Bool) #

Aggregation function SOME.

over :: SqlProjectable (Projection c) => Projection OverWindow a -> Window c () -> Projection c a infix 8 #

Operator to make window function result projection using built `Window`

monad.

rank :: Integral a => Projection OverWindow a #

*RANK()* term.

denseRank :: Integral a => Projection OverWindow a #

*DENSE_RANK()* term.

rowNumber :: Integral a => Projection OverWindow a #

*ROW_NUMBER()* term.

percentRank :: Projection OverWindow Double #

*PERCENT_RANK()* term.

cumeDist :: Projection OverWindow Double #

*CUME_DIST()* term.

## Set Operators

Several operators are defined to manipulate relation set.

`union`

operator makes union relation set of two relation set correspond to SQL UNION.
`except`

operator makes difference relation set of two relation set correspond to SQL EXCEPT.
`intersect`

operator makes intersection relation set of two relation set correspond to SQL INTERSECT.

intersect :: Relation () a -> Relation () a -> Relation () a infixl 8 #

Intersection of two relations.

## Maybe Projections

Some operators are provided to manage projections with `Maybe`

phantom type.

`just`

operator creates `Maybe`

typed projection,
`flattenMaybe`

operator joins nested `Maybe`

typed projection.

`Maybe`

type flavor of operators against projection path, projection and aggregation are also provided.

For example,
`?!`

operator is maybe flavor of `!`

,
`<?.>`

operator is maybe flavor of `<.>`

.
`?!?`

operator and `<?.?>`

operator `join`

two `Maybe`

phantom functors.

`?+?`

operator is maybe flavor of `.+.`

,
`negateMaybe`

operator is maybe flavor of `negate'`

,
`sumMaybe`

operator is maybe flavor of `sum'`

.

Module Database.Relational.Query.Projectable and Database.Relational.Query.ProjectableExtended
contain documentation of other `Maybe`

flavor projection operators.

just :: ProjectableMaybe p => forall a. p a -> p (Maybe a) #

Cast projection phantom type into `Maybe`

.

flattenMaybe :: ProjectableMaybe p => forall a. p (Maybe (Maybe a)) -> p (Maybe a) #

Compose nested `Maybe`

phantom type on projection.

:: Projection c (Maybe a) | Source |

-> Pi a b | Projection path |

-> Projection c (Maybe b) | Narrower projected object. |

:: Projection c (Maybe a) | Source |

-> Pi a (Maybe b) | Projection path. |

-> Projection c (Maybe b) | Narrower projected object. |

(<?.?>) :: Pi a (Maybe b) -> Pi b (Maybe c) -> Pi a (Maybe c) infixl 8 #

Compose projection path. `Maybe`

phantom functors are `join`

-ed like `>=>`

.

(?+?) :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p (Maybe a) -> p (Maybe a) -> p (Maybe a) infixl 6 #

Number operator corresponding SQL *+* .

negateMaybe :: (OperatorProjectable p, ProjectableShowSql p, Num a) => p (Maybe a) -> p (Maybe a) #

Number negate uni-operator corresponding SQL *-*.

sumMaybe :: (Num a, AggregatedContext ac, SqlProjectable (p ac)) => Projection Flat (Maybe a) -> p ac (Maybe a) #

Aggregation function SUM.

## Placeholders

`placeholders`

operator takes
a lambda-form which argument is `Projection`

typed placeholders and its scope is restricted by that lambda-form
and then creates dummy value with `Placeholders`

typed which propagate placeholder type information into `Relation`

layer.

Placeholders' flavor of operators against query operation and set operation are also provided, to realize type safe placeholders.

`query'`

, `left'`

, `relation'`

, `updateTarget'`

, `restriction'`

, and `union'`

operator are placeholders' flavor `query`

, `left`

, `relation`

, `updateTarget`

, `restriction`

and `union`

.

Module Database.Relational.Query.Relation and Database.Relational.Query.Effect contains documentation of other placeholders' flavor operators.

placeholder :: (PersistableWidth t, SqlProjectable p, Monad m) => (p t -> m a) -> m (PlaceHolders t, a) #

Provide scoped placeholder and return its parameter object. Monadic version.

query' :: MonadQuery m => forall p r. Relation p r -> m (PlaceHolders p, Projection Flat r) #

Join sub-query with place-holder parameter `p`

. query result is not `Maybe`

.

:: Relation pa a | Left query to join |

-> Relation pb b | Right query to join |

-> [JoinRestriction a (Maybe b)] | Join restrictions |

-> Relation (pa, pb) (a, Maybe b) | Result joined relation |

Direct left outer join with place-holder parameters.

relation' :: SimpleQuery p r -> Relation p r #

Finalize `QuerySimple`

monad and generate `Relation`

with place-holder parameter `p`

.

updateTarget' :: AssignStatement r (PlaceHolders p) -> UpdateTarget p r #

Finalize `Target`

monad and generate `UpdateTarget`

with place-holder parameter `p`

.

restriction' :: RestrictedStatement r (PlaceHolders p) -> Restriction p r #

Finalize `Restrict`

monad and generate `Restriction`

with place-holder parameter `p`

union' :: Relation p a -> Relation q a -> Relation (p, q) a infixl 7 #

Union of two relations with place-holder parameters.

## Record Mapping

Applicative style record mapping is supported, for `Projection`

, `Pi`

and `PlaceHolders`

.
`|$|`

operator can be used on `ProjectableFunctor`

context, and
`|*|`

operator can be used on `ProjectableApplicative`

context with `ProductConstructor`

,
like *Foo |$| projection1 |*| projection2 |*| projection3*
, *Foo |$| placeholders1 |*| placeholders2 |*| placeholders3*, and so on.

`><`

operator constructs pair result. *x >< y* is the same as *(,) |$| x |*| y*.

class ProductConstructor r #

Specify tuple like record constructors which are allowed to define `ProjectableFunctor`

.

class ProjectableFunctor p where #

Weaken functor on projections.

(|$|) :: ProductConstructor (a -> b) => (a -> b) -> p a -> p b infixl 4 #

Method like `fmap`

.

ProjectableFunctor PlaceHolders | Compose seed of record type |

ProjectableFunctor (Pi a) | Compose seed of projection path |

class ProjectableFunctor p => ProjectableApplicative p where #

Weaken applicative functor on projections.

ProjectableApplicative PlaceHolders | Compose record type |

ProjectableApplicative (Pi a) | Compose projection path |

(><) :: ProjectableApplicative p => p a -> p b -> p (a, b) infixl 1 #

Binary operator the same as `projectZip`

.

## Database Statements

Some functions are defined to expand query structure into flat SQL statements to be used by database operation.

`relationalQuery`

function converts `Relation`

type info flat SQL query like SELECT statement.

`typedInsert`

function converts `Pi`

key type info flat SQL INSERT statement.

`typedInsertQuery`

function converts `Pi`

key type and `Relation`

type info flat SQL INSERT ... SELECT ... statement.

`typedUpdate`

function converts `UpdateTarget`

type into flat SQL UPDATE statement.

`typedDelete`

function converts `Restriction`

into flat SQL DELETE statement.

`typedKeyUpdate`

function converts `Pi`

key type info flat SQL UPDATE statement.

Some handy table type inferred functions are provided,
`derivedInsert`

, `derivedInsertQuery`

, `derivedUpdate`

and `derivedDelete`

.

typedInsert :: Table r -> Pi r r' -> Insert r' #

typedInsertQuery :: Table r -> Pi r r' -> Relation p r' -> InsertQuery p #

Make typed `InsertQuery`

from columns selector `Table`

, `Pi`

and `Relation`

.

typedUpdate :: Table r -> UpdateTarget p r -> Update p #

Make typed `Update`

using `defaultConfig`

, `Table`

and `UpdateTarget`

.

typedDelete :: Table r -> Restriction p r -> Delete p #

Make typed `Delete`

from `Table`

and `Restriction`

.

typedKeyUpdate :: Table a -> Pi a p -> KeyUpdate p a #

derivedInsert :: TableDerivable r => Pi r r' -> Insert r' #

Table type inferred `Insert`

.

derivedInsertQuery :: TableDerivable r => Pi r r' -> Relation p r' -> InsertQuery p #

Table type inferred `InsertQuery`

.

derivedUpdate :: TableDerivable r => AssignStatement r (PlaceHolders p) -> Update p #

Make typed `Update`

from `defaultConfig`

, derived table and `AssignStatement`

derivedDelete :: TableDerivable r => RestrictedStatement r (PlaceHolders p) -> Delete p #

Make typed `Delete`

from `defaultConfig`

, derived table and `RestrictContext`

# Database Operations

Some HDBC actions are defined for database side effects.

## Conversion interfaces to communicate with database

Some record conversion interfaces are defined to communicate with database.

The conversions are implicitly specified by `FromSql`

class and `ToSql`

class.
Generic programming with default signature is available to define instances of `FromSql`

and `ToSql`

.

The explicit definitions correnponsing those classes are `RecordFromSql`

and `RecordToSql`

.

Inference rule interface for `RecordFromSql`

proof object.

FromSql q () | Inference rule of |

(HasColumnConstraint NotNull a, FromSql q a, PersistableType q) => FromSql q (Maybe a) | Inference rule of |

Inference rule interface for `RecordToSql`

proof object.

ToSql q () | Inference rule of |

(PersistableType q, PersistableWidth a, ToSql q a) => ToSql q (Maybe a) | Inference rule of |

data RecordFromSql q a :: * -> * -> * #

Proof object type to convert from sql value type `q`

list into Haskell type `a`

.

Monad (RecordFromSql q) | |

Functor (RecordFromSql q) | |

Applicative (RecordFromSql q) | Derived |

data RecordToSql q a :: * -> * -> * #

Proof object type to convert from Haskell type `a`

into list of SQL type [`q`

].

## Generalized Statement

Actions to manage generalized SQL statements.

prepareNoFetch :: (UntypeableNoFetch s, IConnection conn) => conn -> s p -> IO (PreparedStatement p ()) #

Generalized prepare inferred from `UntypeableNoFetch`

instance.

bind :: ToSql SqlValue p => PreparedStatement p a -> p -> BoundStatement a #

Typed operation to bind parameters. Infered `RecordToSql`

is used.

execute :: BoundStatement a -> IO (ExecutedStatement a) #

Typed execute operation.

executeNoFetch :: BoundStatement () -> IO Integer #

Typed execute operation. Only get result.

## Select

Actions to manage SELECT statements.

`runQuery`

function is lazy-read and `runQuery'`

function is strict version,
please use carefully.

:: IConnection conn | |

=> conn | Database connection |

-> Query p a | Typed query |

-> IO (PreparedQuery p a) | Result typed prepared query with parameter type |

Same as `prepare`

.

:: (IConnection conn, ToSql SqlValue p, FromSql SqlValue a) | |

=> conn | Database connection |

-> Query p a | Query to get record type |

-> p | Parameter type |

-> IO [a] | Action to get records |

Prepare SQL, bind parameters, execute statement and lazily fetch all records.

:: (IConnection conn, ToSql SqlValue p, FromSql SqlValue a) | |

=> conn | Database connection |

-> Query p a | Query to get record type |

-> p | Parameter type |

-> IO [a] | Action to get records |

Strict version of `runQuery`

.

## Insert Values

Actions to manage INSERT ... VALUES ... statements.

prepareInsert :: IConnection conn => conn -> Insert a -> IO (PreparedInsert a) #

Same as `prepare`

.

runInsert :: (IConnection conn, ToSql SqlValue a) => conn -> Insert a -> a -> IO Integer #

Prepare insert statement, bind parameters, execute statement and get execution result.

## Insert Select Results

Actions to manage INSERT ... SELECT ... statements.

prepareInsertQuery :: IConnection conn => conn -> InsertQuery p -> IO (PreparedInsertQuery p) #

Same as `prepare`

.

runInsertQuery :: (IConnection conn, ToSql SqlValue p) => conn -> InsertQuery p -> p -> IO Integer #

Prepare insert statement, bind parameters, execute statement and get execution result.

## Update

Actions to manage UPDATE statements.

prepareUpdate :: IConnection conn => conn -> Update p -> IO (PreparedUpdate p) #

Same as `prepare`

.

runUpdate :: (IConnection conn, ToSql SqlValue p) => conn -> Update p -> p -> IO Integer #

Prepare update statement, bind parameters, execute statement and get execution result.

## Delete

Actions to manage DELETE statements.

prepareDelete :: IConnection conn => conn -> Delete p -> IO (PreparedDelete p) #

Same as `prepare`

.

runDelete :: (IConnection conn, ToSql SqlValue p) => conn -> Delete p -> p -> IO Integer #

Prepare delete statement, bind parameters, execute statement and get execution result.

## Update by Key

Actions to manage UPDATE statements which updates columns other than specified key of the records selected by specified key.

prepareKeyUpdate :: IConnection conn => conn -> KeyUpdate p a -> IO (PreparedKeyUpdate p a) #

Same as `prepare`

.

bindKeyUpdate :: ToSql SqlValue a => PreparedKeyUpdate p a -> a -> BoundStatement () #

Typed operation to bind parameters for `PreparedKeyUpdate`

type.

runKeyUpdate :: (IConnection conn, ToSql SqlValue a) => conn -> KeyUpdate p a -> a -> IO Integer #

Prepare insert statement, bind parameters, execute statement and get execution result.