Database.Persist.Join

Typeclass

class PersistBackend b m => RunJoin a b m where

Associated Types

type Result a

Methods

runJoin :: a -> b m (Result a)

Instances

(PersistEntity one, PersistEntity many, Ord (Key backend one), PersistBackend backend monad) => RunJoin (SelectOneMany backend one many) backend monad

One-to-many relation

data SelectOneMany backend one many

Constructors

SelectOneMany

Fields

somFilterOne :: [Filter one]

somOrderOne :: [SelectOpt one]

somFilterMany :: [Filter many]

somOrderMany :: [SelectOpt many]

somFilterKeys :: [Key backend one] -> Filter many

somGetKey :: many -> Key backend one

somIncludeNoMatch :: Bool

Instances

(PersistEntity one, PersistEntity many, Eq (Key SqlPersist one)) => RunJoin (SelectOneMany SqlPersist one many)

(PersistEntity one, PersistEntity many, Ord (Key backend one), PersistBackend backend monad) => RunJoin (SelectOneMany backend one many) backend monad

selectOneMany :: ([Key backend one] -> Filter many) -> (many -> Key backend one) -> SelectOneMany backend one many