selda-0.1.4.0: Type-safe, high-level EDSL for interacting with relational databases.

Safe HaskellNone
LanguageHaskell2010

Database.Selda.Generic

Description

Build tables and database operations from (almost) any Haskell type.

While the types in this module may look somewhat intimidating, the rules for generic tables and queries are quite simple:

  • Any record type with a single data constructor, where all fields are instances of SqlType, can be used for generic tables and queries if it derives Generic.
  • To use the standard functions from Database.Selda on a generic table, it needs to be unwrapped using gen.
  • Performing a select on a generic table returns all the table's fields as an inductive tuple.
  • Tuples obtained this way can be handled either as any other tuple, or using the ! operator together with any record selector for the tuple's corresponding type.
  • Relations obtained from a query can be re-assembled into their corresponding data type using fromRel.

Synopsis

Documentation

type Relational a = (Generic a, GRelation (Rep a), GFromRel (Rep a), ToDyn (Relation a), Insert (Relation a)) Source #

Any type which has a corresponding relation. To make a Relational instance for some type, simply derive Generic.

Note that only types which have a single data constructor, and where all fields are instances of SqlValue can be used with this module. Attempting to use functions in this module with any type which doesn't obey those constraints will result in a very confusing type error.

class Generic a #

Representable types of kind *. This class is derivable in GHC with the DeriveGeneric flag on.

Minimal complete definition

from, to

Instances

Generic Bool 

Associated Types

type Rep Bool :: * -> * #

Methods

from :: Bool -> Rep Bool x #

to :: Rep Bool x -> Bool #

Generic Ordering 

Associated Types

type Rep Ordering :: * -> * #

Methods

from :: Ordering -> Rep Ordering x #

to :: Rep Ordering x -> Ordering #

Generic Exp 

Associated Types

type Rep Exp :: * -> * #

Methods

from :: Exp -> Rep Exp x #

to :: Rep Exp x -> Exp #

Generic Match 

Associated Types

type Rep Match :: * -> * #

Methods

from :: Match -> Rep Match x #

to :: Rep Match x -> Match #

Generic Clause 

Associated Types

type Rep Clause :: * -> * #

Methods

from :: Clause -> Rep Clause x #

to :: Rep Clause x -> Clause #

Generic Pat 

Associated Types

type Rep Pat :: * -> * #

Methods

from :: Pat -> Rep Pat x #

to :: Rep Pat x -> Pat #

Generic Type 

Associated Types

type Rep Type :: * -> * #

Methods

from :: Type -> Rep Type x #

to :: Rep Type x -> Type #

Generic Dec 

Associated Types

type Rep Dec :: * -> * #

Methods

from :: Dec -> Rep Dec x #

to :: Rep Dec x -> Dec #

Generic Name 

Associated Types

type Rep Name :: * -> * #

Methods

from :: Name -> Rep Name x #

to :: Rep Name x -> Name #

Generic FunDep 

Associated Types

type Rep FunDep :: * -> * #

Methods

from :: FunDep -> Rep FunDep x #

to :: Rep FunDep x -> FunDep #

Generic TyVarBndr 

Associated Types

type Rep TyVarBndr :: * -> * #

Generic InjectivityAnn 

Associated Types

type Rep InjectivityAnn :: * -> * #

Generic Overlap 

Associated Types

type Rep Overlap :: * -> * #

Methods

from :: Overlap -> Rep Overlap x #

to :: Rep Overlap x -> Overlap #

Generic () 

Associated Types

type Rep () :: * -> * #

Methods

from :: () -> Rep () x #

to :: Rep () x -> () #

Generic Void 

Associated Types

type Rep Void :: * -> * #

Methods

from :: Void -> Rep Void x #

to :: Rep Void x -> Void #

Generic Version 

Associated Types

type Rep Version :: * -> * #

Methods

from :: Version -> Rep Version x #

to :: Rep Version x -> Version #

Generic ExitCode 

Associated Types

type Rep ExitCode :: * -> * #

Methods

from :: ExitCode -> Rep ExitCode x #

to :: Rep ExitCode x -> ExitCode #

Generic All 

Associated Types

type Rep All :: * -> * #

Methods

from :: All -> Rep All x #

to :: Rep All x -> All #

Generic Any 

Associated Types

type Rep Any :: * -> * #

Methods

from :: Any -> Rep Any x #

to :: Rep Any x -> Any #

Generic Fixity 

Associated Types

type Rep Fixity :: * -> * #

Methods

from :: Fixity -> Rep Fixity x #

to :: Rep Fixity x -> Fixity #

Generic Associativity 

Associated Types

type Rep Associativity :: * -> * #

Generic SourceUnpackedness 
Generic SourceStrictness 
Generic DecidedStrictness 
Generic Extension 

Associated Types

type Rep Extension :: * -> * #

Generic ModName 

Associated Types

type Rep ModName :: * -> * #

Methods

from :: ModName -> Rep ModName x #

to :: Rep ModName x -> ModName #

Generic PkgName 

Associated Types

type Rep PkgName :: * -> * #

Methods

from :: PkgName -> Rep PkgName x #

to :: Rep PkgName x -> PkgName #

Generic Module 

Associated Types

type Rep Module :: * -> * #

Methods

from :: Module -> Rep Module x #

to :: Rep Module x -> Module #

Generic OccName 

Associated Types

type Rep OccName :: * -> * #

Methods

from :: OccName -> Rep OccName x #

to :: Rep OccName x -> OccName #

Generic NameFlavour 

Associated Types

type Rep NameFlavour :: * -> * #

Generic NameSpace 

Associated Types

type Rep NameSpace :: * -> * #

Generic Loc 

Associated Types

type Rep Loc :: * -> * #

Methods

from :: Loc -> Rep Loc x #

to :: Rep Loc x -> Loc #

Generic Info 

Associated Types

type Rep Info :: * -> * #

Methods

from :: Info -> Rep Info x #

to :: Rep Info x -> Info #

Generic ModuleInfo 

Associated Types

type Rep ModuleInfo :: * -> * #

Generic Fixity 

Associated Types

type Rep Fixity :: * -> * #

Methods

from :: Fixity -> Rep Fixity x #

to :: Rep Fixity x -> Fixity #

Generic FixityDirection 
Generic Lit 

Associated Types

type Rep Lit :: * -> * #

Methods

from :: Lit -> Rep Lit x #

to :: Rep Lit x -> Lit #

Generic Body 

Associated Types

type Rep Body :: * -> * #

Methods

from :: Body -> Rep Body x #

to :: Rep Body x -> Body #

Generic Guard 

Associated Types

type Rep Guard :: * -> * #

Methods

from :: Guard -> Rep Guard x #

to :: Rep Guard x -> Guard #

Generic Stmt 

Associated Types

type Rep Stmt :: * -> * #

Methods

from :: Stmt -> Rep Stmt x #

to :: Rep Stmt x -> Stmt #

Generic Range 

Associated Types

type Rep Range :: * -> * #

Methods

from :: Range -> Rep Range x #

to :: Rep Range x -> Range #

Generic TypeFamilyHead 

Associated Types

type Rep TypeFamilyHead :: * -> * #

Generic TySynEqn 

Associated Types

type Rep TySynEqn :: * -> * #

Methods

from :: TySynEqn -> Rep TySynEqn x #

to :: Rep TySynEqn x -> TySynEqn #

Generic FamFlavour 

Associated Types

type Rep FamFlavour :: * -> * #

Generic Foreign 

Associated Types

type Rep Foreign :: * -> * #

Methods

from :: Foreign -> Rep Foreign x #

to :: Rep Foreign x -> Foreign #

Generic Callconv 

Associated Types

type Rep Callconv :: * -> * #

Methods

from :: Callconv -> Rep Callconv x #

to :: Rep Callconv x -> Callconv #

Generic Safety 

Associated Types

type Rep Safety :: * -> * #

Methods

from :: Safety -> Rep Safety x #

to :: Rep Safety x -> Safety #

Generic Pragma 

Associated Types

type Rep Pragma :: * -> * #

Methods

from :: Pragma -> Rep Pragma x #

to :: Rep Pragma x -> Pragma #

Generic Inline 

Associated Types

type Rep Inline :: * -> * #

Methods

from :: Inline -> Rep Inline x #

to :: Rep Inline x -> Inline #

Generic RuleMatch 

Associated Types

type Rep RuleMatch :: * -> * #

Generic Phases 

Associated Types

type Rep Phases :: * -> * #

Methods

from :: Phases -> Rep Phases x #

to :: Rep Phases x -> Phases #

Generic RuleBndr 

Associated Types

type Rep RuleBndr :: * -> * #

Methods

from :: RuleBndr -> Rep RuleBndr x #

to :: Rep RuleBndr x -> RuleBndr #

Generic AnnTarget 

Associated Types

type Rep AnnTarget :: * -> * #

Generic SourceUnpackedness 
Generic SourceStrictness 
Generic DecidedStrictness 
Generic Con 

Associated Types

type Rep Con :: * -> * #

Methods

from :: Con -> Rep Con x #

to :: Rep Con x -> Con #

Generic Bang 

Associated Types

type Rep Bang :: * -> * #

Methods

from :: Bang -> Rep Bang x #

to :: Rep Bang x -> Bang #

Generic FamilyResultSig 
Generic TyLit 

Associated Types

type Rep TyLit :: * -> * #

Methods

from :: TyLit -> Rep TyLit x #

to :: Rep TyLit x -> TyLit #

Generic Role 

Associated Types

type Rep Role :: * -> * #

Methods

from :: Role -> Rep Role x #

to :: Rep Role x -> Role #

Generic AnnLookup 

Associated Types

type Rep AnnLookup :: * -> * #

Generic [a] 

Associated Types

type Rep [a] :: * -> * #

Methods

from :: [a] -> Rep [a] x #

to :: Rep [a] x -> [a] #

Generic (Maybe a) 

Associated Types

type Rep (Maybe a) :: * -> * #

Methods

from :: Maybe a -> Rep (Maybe a) x #

to :: Rep (Maybe a) x -> Maybe a #

Generic (V1 p) 

Associated Types

type Rep (V1 p) :: * -> * #

Methods

from :: V1 p -> Rep (V1 p) x #

to :: Rep (V1 p) x -> V1 p #

Generic (U1 p) 

Associated Types

type Rep (U1 p) :: * -> * #

Methods

from :: U1 p -> Rep (U1 p) x #

to :: Rep (U1 p) x -> U1 p #

Generic (Par1 p) 

Associated Types

type Rep (Par1 p) :: * -> * #

Methods

from :: Par1 p -> Rep (Par1 p) x #

to :: Rep (Par1 p) x -> Par1 p #

Generic (Identity a) 

Associated Types

type Rep (Identity a) :: * -> * #

Methods

from :: Identity a -> Rep (Identity a) x #

to :: Rep (Identity a) x -> Identity a #

Generic (Min a) 

Associated Types

type Rep (Min a) :: * -> * #

Methods

from :: Min a -> Rep (Min a) x #

to :: Rep (Min a) x -> Min a #

Generic (Max a) 

Associated Types

type Rep (Max a) :: * -> * #

Methods

from :: Max a -> Rep (Max a) x #

to :: Rep (Max a) x -> Max a #

Generic (First a) 

Associated Types

type Rep (First a) :: * -> * #

Methods

from :: First a -> Rep (First a) x #

to :: Rep (First a) x -> First a #

Generic (Last a) 

Associated Types

type Rep (Last a) :: * -> * #

Methods

from :: Last a -> Rep (Last a) x #

to :: Rep (Last a) x -> Last a #

Generic (WrappedMonoid m) 

Associated Types

type Rep (WrappedMonoid m) :: * -> * #

Generic (Option a) 

Associated Types

type Rep (Option a) :: * -> * #

Methods

from :: Option a -> Rep (Option a) x #

to :: Rep (Option a) x -> Option a #

Generic (NonEmpty a) 

Associated Types

type Rep (NonEmpty a) :: * -> * #

Methods

from :: NonEmpty a -> Rep (NonEmpty a) x #

to :: Rep (NonEmpty a) x -> NonEmpty a #

Generic (Complex a) 

Associated Types

type Rep (Complex a) :: * -> * #

Methods

from :: Complex a -> Rep (Complex a) x #

to :: Rep (Complex a) x -> Complex a #

Generic (ZipList a) 

Associated Types

type Rep (ZipList a) :: * -> * #

Methods

from :: ZipList a -> Rep (ZipList a) x #

to :: Rep (ZipList a) x -> ZipList a #

Generic (Dual a) 

Associated Types

type Rep (Dual a) :: * -> * #

Methods

from :: Dual a -> Rep (Dual a) x #

to :: Rep (Dual a) x -> Dual a #

Generic (Endo a) 

Associated Types

type Rep (Endo a) :: * -> * #

Methods

from :: Endo a -> Rep (Endo a) x #

to :: Rep (Endo a) x -> Endo a #

Generic (Sum a) 

Associated Types

type Rep (Sum a) :: * -> * #

Methods

from :: Sum a -> Rep (Sum a) x #

to :: Rep (Sum a) x -> Sum a #

Generic (Product a) 

Associated Types

type Rep (Product a) :: * -> * #

Methods

from :: Product a -> Rep (Product a) x #

to :: Rep (Product a) x -> Product a #

Generic (First a) 

Associated Types

type Rep (First a) :: * -> * #

Methods

from :: First a -> Rep (First a) x #

to :: Rep (First a) x -> First a #

Generic (Last a) 

Associated Types

type Rep (Last a) :: * -> * #

Methods

from :: Last a -> Rep (Last a) x #

to :: Rep (Last a) x -> Last a #

Generic (Either a b) 

Associated Types

type Rep (Either a b) :: * -> * #

Methods

from :: Either a b -> Rep (Either a b) x #

to :: Rep (Either a b) x -> Either a b #

Generic (Rec1 f p) 

Associated Types

type Rep (Rec1 f p) :: * -> * #

Methods

from :: Rec1 f p -> Rep (Rec1 f p) x #

to :: Rep (Rec1 f p) x -> Rec1 f p #

Generic (URec Char p) 

Associated Types

type Rep (URec Char p) :: * -> * #

Methods

from :: URec Char p -> Rep (URec Char p) x #

to :: Rep (URec Char p) x -> URec Char p #

Generic (URec Double p) 

Associated Types

type Rep (URec Double p) :: * -> * #

Methods

from :: URec Double p -> Rep (URec Double p) x #

to :: Rep (URec Double p) x -> URec Double p #

Generic (URec Float p) 

Associated Types

type Rep (URec Float p) :: * -> * #

Methods

from :: URec Float p -> Rep (URec Float p) x #

to :: Rep (URec Float p) x -> URec Float p #

Generic (URec Int p) 

Associated Types

type Rep (URec Int p) :: * -> * #

Methods

from :: URec Int p -> Rep (URec Int p) x #

to :: Rep (URec Int p) x -> URec Int p #

Generic (URec Word p) 

Associated Types

type Rep (URec Word p) :: * -> * #

Methods

from :: URec Word p -> Rep (URec Word p) x #

to :: Rep (URec Word p) x -> URec Word p #

Generic (URec (Ptr ()) p) 

Associated Types

type Rep (URec (Ptr ()) p) :: * -> * #

Methods

from :: URec (Ptr ()) p -> Rep (URec (Ptr ()) p) x #

to :: Rep (URec (Ptr ()) p) x -> URec (Ptr ()) p #

Generic (a, b) 

Associated Types

type Rep (a, b) :: * -> * #

Methods

from :: (a, b) -> Rep (a, b) x #

to :: Rep (a, b) x -> (a, b) #

Generic (Arg a b) 

Associated Types

type Rep (Arg a b) :: * -> * #

Methods

from :: Arg a b -> Rep (Arg a b) x #

to :: Rep (Arg a b) x -> Arg a b #

Generic (WrappedMonad m a) 

Associated Types

type Rep (WrappedMonad m a) :: * -> * #

Methods

from :: WrappedMonad m a -> Rep (WrappedMonad m a) x #

to :: Rep (WrappedMonad m a) x -> WrappedMonad m a #

Generic (Proxy k t) 

Associated Types

type Rep (Proxy k t) :: * -> * #

Methods

from :: Proxy k t -> Rep (Proxy k t) x #

to :: Rep (Proxy k t) x -> Proxy k t #

Generic ((:*:) a b) # 

Associated Types

type Rep ((:*:) a b) :: * -> * #

Methods

from :: (a :*: b) -> Rep (a :*: b) x #

to :: Rep (a :*: b) x -> a :*: b #

Generic (K1 i c p) 

Associated Types

type Rep (K1 i c p) :: * -> * #

Methods

from :: K1 i c p -> Rep (K1 i c p) x #

to :: Rep (K1 i c p) x -> K1 i c p #

Generic ((:+:) f g p) 

Associated Types

type Rep ((:+:) f g p) :: * -> * #

Methods

from :: (f :+: g) p -> Rep ((f :+: g) p) x #

to :: Rep ((f :+: g) p) x -> (f :+: g) p #

Generic ((:*:) f g p) 

Associated Types

type Rep ((:*:) f g p) :: * -> * #

Methods

from :: (f :*: g) p -> Rep ((f :*: g) p) x #

to :: Rep ((f :*: g) p) x -> (f :*: g) p #

Generic ((:.:) f g p) 

Associated Types

type Rep ((:.:) f g p) :: * -> * #

Methods

from :: (f :.: g) p -> Rep ((f :.: g) p) x #

to :: Rep ((f :.: g) p) x -> (f :.: g) p #

Generic (a, b, c) 

Associated Types

type Rep (a, b, c) :: * -> * #

Methods

from :: (a, b, c) -> Rep (a, b, c) x #

to :: Rep (a, b, c) x -> (a, b, c) #

Generic (WrappedArrow a b c) 

Associated Types

type Rep (WrappedArrow a b c) :: * -> * #

Methods

from :: WrappedArrow a b c -> Rep (WrappedArrow a b c) x #

to :: Rep (WrappedArrow a b c) x -> WrappedArrow a b c #

Generic (Const k a b) 

Associated Types

type Rep (Const k a b) :: * -> * #

Methods

from :: Const k a b -> Rep (Const k a b) x #

to :: Rep (Const k a b) x -> Const k a b #

Generic (Alt k f a) 

Associated Types

type Rep (Alt k f a) :: * -> * #

Methods

from :: Alt k f a -> Rep (Alt k f a) x #

to :: Rep (Alt k f a) x -> Alt k f a #

Generic (M1 i c f p) 

Associated Types

type Rep (M1 i c f p) :: * -> * #

Methods

from :: M1 i c f p -> Rep (M1 i c f p) x #

to :: Rep (M1 i c f p) x -> M1 i c f p #

Generic (a, b, c, d) 

Associated Types

type Rep (a, b, c, d) :: * -> * #

Methods

from :: (a, b, c, d) -> Rep (a, b, c, d) x #

to :: Rep (a, b, c, d) x -> (a, b, c, d) #

Generic (Sum k f g a) 

Associated Types

type Rep (Sum k f g a) :: * -> * #

Methods

from :: Sum k f g a -> Rep (Sum k f g a) x #

to :: Rep (Sum k f g a) x -> Sum k f g a #

Generic (Product k f g a) 

Associated Types

type Rep (Product k f g a) :: * -> * #

Methods

from :: Product k f g a -> Rep (Product k f g a) x #

to :: Rep (Product k f g a) x -> Product k f g a #

Generic (a, b, c, d, e) 

Associated Types

type Rep (a, b, c, d, e) :: * -> * #

Methods

from :: (a, b, c, d, e) -> Rep (a, b, c, d, e) x #

to :: Rep (a, b, c, d, e) x -> (a, b, c, d, e) #

Generic (Compose k1 k f g a) 

Associated Types

type Rep (Compose k1 k f g a) :: * -> * #

Methods

from :: Compose k1 k f g a -> Rep (Compose k1 k f g a) x #

to :: Rep (Compose k1 k f g a) x -> Compose k1 k f g a #

Generic (a, b, c, d, e, f) 

Associated Types

type Rep (a, b, c, d, e, f) :: * -> * #

Methods

from :: (a, b, c, d, e, f) -> Rep (a, b, c, d, e, f) x #

to :: Rep (a, b, c, d, e, f) x -> (a, b, c, d, e, f) #

Generic (a, b, c, d, e, f, g) 

Associated Types

type Rep (a, b, c, d, e, f, g) :: * -> * #

Methods

from :: (a, b, c, d, e, f, g) -> Rep (a, b, c, d, e, f, g) x #

to :: Rep (a, b, c, d, e, f, g) x -> (a, b, c, d, e, f, g) #

data GenAttr a where Source #

A generic column attribute. Essentially a pair or a record selector over the type a and a column attribute.

Constructors

(:-) :: (a -> b) -> Attribute -> GenAttr a 

newtype GenTable a Source #

A generic table. Needs to be unpacked using gen before use with select, insert, etc.

Constructors

GenTable 

Fields

data Attribute Source #

Some attribute that may be set on a table column.

type Relation a = Rel (Rep a) Source #

The relation corresponding to the given Haskell type. This relation simply corresponds to the fields in the data type, from left to right. For instance:

data Foo = Foo
  { bar :: Int
  , baz :: Text
  }

In this example, Relation Foo is (Int :*: Text), as the first field of Foo has type Int, and the second has type Text.

genTable :: forall a. Relational a => TableName -> [GenAttr a] -> GenTable a Source #

Generate a table from the given table name and list of column attributes. All Maybe fields in the table's type will be represented by nullable columns, and all non-Maybe fields fill be represented by required columns. For example:

data Person = Person
  { id   :: Int
  , name :: Text
  , age  :: Int
  , pet  :: Maybe Text
  }
  deriving Generic

people :: GenTable Person
people = genTable "people" [(name, autoPrimaryGen)]

This example will create a table with the column types Int :*: Text :*: Int :*: Maybe Text, where the first field is an auto-incrementing primary key.

toRel :: Relational a => a -> Relation a Source #

Convert a generic type into the corresponding database relation. A type's corresponding relation is simply the inductive tuple consisting of all of the type's fields.

data Person = Person
  { id   :: Int
  , name :: Text
  , age  :: Int
  , pet  :: Maybe Text
  }
  deriving Generic

somePerson = Person 0 "Velvet" 19 Nothing
(theId :*: theName :*: theAge :*: thePet) = toRel somePerson

This is mainly useful when inserting values into a table using insert and the other functions from Database.Selda.

toRels :: Relational a => [a] -> [Relation a] Source #

Convenient synonym for map toRel.

fromRel :: Relational a => Relation a -> a Source #

Re-assemble a generic type from its corresponding relation. This can be done either for ad hoc queries or for queries over generic tables:

data SimplePerson = SimplePerson
  { name :: Text
  , age  :: Int
  }
  deriving Generic

demoPerson :: SimplePerson
demoPerson = fromRel ("Miyu" :*: 10)

adhoc :: Table (Text :*: Int)
adhoc = table "adhoc" $ required "name" ¤ required "age"

getPersons1 :: MonadSelda m => m [SimplePerson]
getPersons1 = map fromRel <$> query (select adhoc)

generic :: GenTable SimplePerson
generic = genTable "generic" []

getPersons2 :: MonadSelda m => m [SimplePerson]
getPersons2 = map fromRel <$> query (select (gen generic))

Applying toRel to an inductive tuple which isn't the corresponding relation of the return type is a type error.

fromRels :: Relational a => [Relation a] -> [a] Source #

Convenient synonym for map fromRel.

insertGen :: (Relational a, MonadSelda m) => GenTable a -> [a] -> m Int Source #

Like insert, but accepts a generic table and its corresponding data type.

insertGen_ :: (Relational a, MonadSelda m) => GenTable a -> [a] -> m () Source #

Like insert_, but accepts a generic table and its corresponding data type.

insertGenWithPK :: (Relational a, MonadSelda m) => GenTable a -> [a] -> m Int Source #

Like insertWithPK, but accepts a generic table and its corresponding data type.

primaryGen :: Attribute Source #

A primary key which does not auto-increment.

autoPrimaryGen :: Attribute Source #

An auto-incrementing primary key.