@@ -25,6 +25,8 @@ import Data.Text ( Text )
25import qualified Data.Text.Lazy as Lazy ( Text )
25import qualified Data.Text.Lazy as Lazy ( Text )
28+-- | The class of data types that support the @string_agg()@ aggregation
28type DBString :: Type -> Constraint
30type DBString :: Type -> Constraint
29class DBType a => DBString a
31class DBType a => DBString a
30instance DBString Text
32instance DBString Text