Hoogle Search

Within LTS Haskell 24.10 (ghc-9.10.2)

Note that Stackage only displays results for the latest LTS and Nightly snapshot. Learn more.

Exact lookup

1. mkPersist :: MkPersistSettings -> [UnboundEntityDef] -> Q [Dec]

   persistent	Database.Persist.TH.Internal

   Create data types and appropriate PersistEntity instances for the given UnboundEntityDefs. This function should be used if you are only defining a single block of Persistent models for the entire application. If you intend on defining multiple blocks in different fiels, see mkPersistWith which allows you to provide existing entity definitions so foreign key references work. Example:

   mkPersist sqlSettings [persistLowerCase|
   User
   name    Text
   age     Int
   
   Dog
   name    Text
   owner   UserId
   
   |]
   

   Example from a file:

   mkPersist sqlSettings $(persistFileWith lowerCaseSettings "models.persistentmodels")
   

   For full information on the QuasiQuoter syntax, see Database.Persist.Quasi documentation.

2. mkPersistSettings :: Type -> MkPersistSettings

   persistent	Database.Persist.TH.Internal

   Create an MkPersistSettings with default values.

3. mkPersistWith :: MkPersistSettings -> [EntityDef] -> [UnboundEntityDef] -> Q [Dec]

   persistent	Database.Persist.TH.Internal

   Like mkPersist, but allows you to provide a [EntityDef] representing the predefined entities. This function will include those EntityDef when looking for foreign key references. You should use this if you intend on defining Persistent models in multiple files. Suppose we define a table Foo which has no dependencies.

   module DB.Foo where
   
   mkPersistWith sqlSettings [] [persistLowerCase|
   Foo
   name    Text
   |]
   

   Then, we define a table Bar which depends on Foo:

   module DB.Bar where
   
   import DB.Foo
   
   mkPersistWith sqlSettings [entityDef (Proxy :: Proxy Foo)] [persistLowerCase|
   Bar
   fooId  FooId
   |]
   

   Writing out the list of EntityDef can be annoying. The $(discoverEntities) shortcut will work to reduce this boilerplate.

   module DB.Quux where
   
   import DB.Foo
   import DB.Bar
   
   mkPersistWith sqlSettings $(discoverEntities) [persistLowerCase|
   Quux
   name     Text
   fooId    FooId
   barId    BarId
   |]
   

4. class HasPersistBackend backend

   esqueleto	Database.Esqueleto

   Class which allows the plucking of a BaseBackend backend from some larger type. For example, instance HasPersistBackend (SqlReadBackend, Int) where type BaseBackend (SqlReadBackend, Int) = SqlBackend persistBackend = unSqlReadBackend . fst

5. class HasPersistBackend backend => IsPersistBackend backend

   esqueleto	Database.Esqueleto

   Class which witnesses that backend is essentially the same as BaseBackend backend. That is, they're isomorphic and backend is just some wrapper over BaseBackend backend.

6. type SqlPersistM = SqlPersistT NoLoggingT ResourceT IO

   esqueleto	Database.Esqueleto

   No documentation available.

7. type SqlPersistT = ReaderT SqlBackend

   esqueleto	Database.Esqueleto

   No documentation available.

8. fromPersistValue :: PersistField a => PersistValue -> Either Text a

   esqueleto	Database.Esqueleto

   No documentation available.

9. fromPersistValueJSON :: FromJSON a => PersistValue -> Either Text a

   esqueleto	Database.Esqueleto

   Convenience function for getting a free PersistField instance from a type with JSON instances. The JSON parser used will accept JSON values other that object and arrays. So, if your instance serializes the data to a JSON string, this will still work. Example usage in combination with toPersistValueJSON:

   instance PersistField MyData where
   fromPersistValue = fromPersistValueJSON
   toPersistValue = toPersistValueJSON
   

10. fromPersistValueText :: PersistValue -> Either Text Text

    esqueleto	Database.Esqueleto

    No documentation available.

Page 46 of many | Previous | Next