{-# LANGUAGE
ConstraintKinds
, DeriveGeneric
, DerivingStrategies
, FlexibleContexts
, FlexibleInstances
, GADTs
, GeneralizedNewtypeDeriving
, LambdaCase
, MultiParamTypeClasses
, OverloadedLabels
, OverloadedStrings
, QuantifiedConstraints
, ScopedTypeVariables
, StandaloneDeriving
, TypeApplications
, TypeFamilies
, TypeInType
, TypeOperators
, RankNTypes
, UndecidableInstances
#-}
module Squeal.PostgreSQL.Query.From
(
FromClause (..)
, table
, subquery
, view
, common
) where
import Control.DeepSeq
import Data.ByteString (ByteString)
import qualified GHC.Generics as GHC
import Squeal.PostgreSQL.Type.Alias
import Squeal.PostgreSQL.Query
import Squeal.PostgreSQL.Render
import Squeal.PostgreSQL.Type.List
import Squeal.PostgreSQL.Type.Schema
newtype FromClause
(lat :: FromType)
(with :: FromType)
(db :: SchemasType)
(params :: [NullType])
(from :: FromType)
= UnsafeFromClause { renderFromClause :: ByteString }
deriving stock (GHC.Generic,Show,Eq,Ord)
deriving newtype (NFData)
instance RenderSQL (FromClause lat with db params from) where
renderSQL = renderFromClause
table
:: (Has sch db schema, Has tab schema ('Table table))
=> Aliased (QualifiedAlias sch) (alias ::: tab)
-> FromClause lat with db params '[alias ::: TableToRow table]
table (tab `As` alias) = UnsafeFromClause $
renderSQL tab <+> "AS" <+> renderSQL alias
subquery
:: Aliased (Query lat with db params) query
-> FromClause lat with db params '[query]
subquery = UnsafeFromClause . renderAliased (parenthesized . renderSQL)
view
:: (Has sch db schema, Has vw schema ('View view))
=> Aliased (QualifiedAlias sch) (alias ::: vw)
-> FromClause lat with db params '[alias ::: view]
view (vw `As` alias) = UnsafeFromClause $
renderSQL vw <+> "AS" <+> renderSQL alias
common
:: Has cte with common
=> Aliased Alias (alias ::: cte)
-> FromClause lat with db params '[alias ::: common]
common (cte `As` alias) = UnsafeFromClause $
renderSQL cte <+> "AS" <+> renderSQL alias
instance Additional (FromClause lat with db params) where
also right left = UnsafeFromClause $
renderSQL left <> ", " <> renderSQL right