esqueleto/src/Database/Esqueleto/PostgreSQL.hs
2015-07-15 12:34:47 -03:00

35 lines
816 B
Haskell

{-# LANGUAGE OverloadedStrings
#-}
-- | This module contain PostgreSQL-specific functions.
--
-- /Since: 2.2.8/
module Database.Esqueleto.PostgreSQL
( arrayAgg
, stringAgg
) where
import Data.String (IsString)
import Database.Esqueleto.Internal.Language
import Database.Esqueleto.Internal.Sql
-- | (@array_agg@) Concatenate input values, including @NULL@s,
-- into an array.
--
-- /Since: 2.2.8/
arrayAgg :: SqlExpr (Value a) -> SqlExpr (Value [a])
arrayAgg = unsafeSqlFunction "array_agg"
-- | (@string_agg@) Concatenate input values separated by a
-- delimiter.
--
-- /Since: 2.2.8/
stringAgg
:: IsString s
=> SqlExpr (Value s) -- ^ Input values.
-> SqlExpr (Value s) -- ^ Delimiter.
-> SqlExpr (Value s) -- ^ Concatenation.
stringAgg expr delim = unsafeSqlFunction "string_agg" (expr, delim)