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GHC 10.0.0.20260917 · lts/ghc-10.0.x · 8fef28d · 2026-11-02

Moduleopaleye-0.10.8.0Haskell2010

Opaleye.Internal.Join

Synopsis

newtype NullMaker
value toNullable
value joinExplicit
value leftJoinAExplicit
value optionalRestrict
value optionalRestrictExplicit
value leftJoinInTermsOfOptionalRestrict
value extractLeftJoinFields

Packageopaleye-0.10.8.0
Exports8
LanguageHaskell2010
LicenceBSD-3-Clause
SourceJoin.hs

newtypenewtype NullMaker a b

Constructors

NullMaker (a -> b)

Instances6Profunctor, ProductProfunctor, Default, Functor, Applicative

Profunctor NullMakerDefined in opaleye-0.10.8.0 · Opaleye.Internal.Join
ProductProfunctor NullMakerDefined in opaleye-0.10.8.0 · Opaleye.Internal.Join
Default NullMaker (Field a) (FieldNullable a)Defined in opaleye-0.10.8.0 · Opaleye.Internal.Join
Default NullMaker (FieldNullable a) (FieldNullable a)Defined in opaleye-0.10.8.0 · Opaleye.Internal.Join
Functor (NullMaker a)Defined in opaleye-0.10.8.0 · Opaleye.Internal.Join
Applicative (NullMaker a)Defined in opaleye-0.10.8.0 · Opaleye.Internal.Join

valuetoNullable :: NullMaker a b -> a -> b

valuejoinExplicit

:: Unpackspec columnsA columnsA
-> Unpackspec columnsB columnsB
-> columnsA -> returnedColumnsA
-> columnsB -> returnedColumnsB
-> JoinType
-> Query columnsA
-> Query columnsB
-> (columnsA, columnsB) -> Field PGBool
-> Query (returnedColumnsA, returnedColumnsB)

valueleftJoinAExplicit

:: Unpackspec a a
-> NullMaker a nullableA
-> Query a
-> QueryArr (a -> Field PGBool) nullableA

valueoptionalRestrict

:: Default Unpackspec a a
=> Select a
-> SelectArr (a -> Field SqlBool) (MaybeFields a)

valueoptionalRestrictExplicit

:: Unpackspec a a
-> Select a
-> SelectArr (a -> Field SqlBool) (MaybeFields a)

valueleftJoinInTermsOfOptionalRestrict

:: Default Unpackspec fieldsR fieldsR
=> Select fieldsL
-> Select fieldsR
-> (fieldsL, fieldsR) -> Field SqlBool
-> Select (fieldsL, MaybeFields fieldsR)

An example to demonstrate how the functionality of LEFT JOIN can be recovered using optionalRestrict.

valueextractLeftJoinFields

:: Int
-> Tag
-> PrimExpr
-> PM [(Symbol, PrimExpr)] PrimExpr