persistent-1.2.1.1: Type-safe, multi-backend data serialization.

Safe HaskellNone

Database.Persist.Class

Synopsis

Documentation

class (PersistStore m, PersistEntity a, PersistEntityBackend a ~ PersistMonadBackend m) => DeleteCascade a m whereSource

Methods

deleteCascade :: Key a -> m ()Source

class PersistEntity val whereSource

A single database entity. For example, if writing a blog application, a blog entry would be an entry, containing fields such as title and content.

Associated Types

data EntityField val :: * -> *Source

Parameters: val and datatype of the field

type PersistEntityBackend val Source

data Unique val Source

Unique keys in existence on this entity.

Methods

persistFieldDef :: EntityField val typ -> FieldDef SqlTypeSource

entityDef :: Monad m => m val -> EntityDef SqlTypeSource

toPersistFields :: val -> [SomePersistField]Source

fromPersistValues :: [PersistValue] -> Either Text valSource

persistUniqueToFieldNames :: Unique val -> [(HaskellName, DBName)]Source

persistUniqueToValues :: Unique val -> [PersistValue]Source

persistUniqueKeys :: val -> [Unique val]Source

persistIdField :: EntityField val (Key val)Source

fieldLens :: EntityField val field -> forall f. Functor f => (field -> f field) -> Entity val -> f (Entity val)Source

class PersistStore m => PersistQuery m whereSource

Methods

update :: (PersistEntity val, PersistEntityBackend val ~ PersistMonadBackend m) => Key val -> [Update val] -> m ()Source

Update individual fields on a specific record.

updateGet :: (PersistEntity val, PersistMonadBackend m ~ PersistEntityBackend val) => Key val -> [Update val] -> m valSource

Update individual fields on a specific record, and retrieve the updated value from the database.

Note that this function will throw an exception if the given key is not found in the database.

updateWhere :: (PersistEntity val, PersistEntityBackend val ~ PersistMonadBackend m) => [Filter val] -> [Update val] -> m ()Source

Update individual fields on any record matching the given criterion.

deleteWhere :: (PersistEntity val, PersistEntityBackend val ~ PersistMonadBackend m) => [Filter val] -> m ()Source

Delete all records matching the given criterion.

selectSource :: (PersistEntity val, PersistEntityBackend val ~ PersistMonadBackend m) => [Filter val] -> [SelectOpt val] -> Source m (Entity val)Source

Get all records matching the given criterion in the specified order. Returns also the identifiers.

selectFirst :: (PersistEntity val, PersistEntityBackend val ~ PersistMonadBackend m) => [Filter val] -> [SelectOpt val] -> m (Maybe (Entity val))Source

get just the first record for the criterion

selectKeys :: (PersistEntity val, PersistEntityBackend val ~ PersistMonadBackend m) => [Filter val] -> [SelectOpt val] -> Source m (Key val)Source

Get the Keys of all records matching the given criterion.

count :: (PersistEntity val, PersistEntityBackend val ~ PersistMonadBackend m) => [Filter val] -> m IntSource

The total number of records fulfilling the given criterion.

Instances

class PersistStore m => PersistUnique m whereSource

Queries against unique keys (other than the id).

Please read the general Persistent documentation to learn how to create Unique keys. SQL backends automatically create uniqueness constraints, but for MongoDB you must place a unique index on the field.

Methods

getBy :: (PersistEntityBackend val ~ PersistMonadBackend m, PersistEntity val) => Unique val -> m (Maybe (Entity val))Source

Get a record by unique key, if available. Returns also the identifier.

deleteBy :: (PersistEntityBackend val ~ PersistMonadBackend m, PersistEntity val) => Unique val -> m ()Source

Delete a specific record by unique key. Does nothing if no record matches.

insertUnique :: (PersistEntityBackend val ~ PersistMonadBackend m, PersistEntity val) => val -> m (Maybe (Key val))Source

Like insert, but returns Nothing when the record couldn't be inserted because of a uniqueness constraint.

Instances

class PersistConfig c whereSource

Represents a value containing all the configuration options for a specific backend. This abstraction makes it easier to write code that can easily swap backends.

Associated Types

type PersistConfigBackend c :: (* -> *) -> * -> *Source

type PersistConfigPool c Source

Methods

loadConfig :: Value -> Parser cSource

Load the config settings from a Value, most likely taken from a YAML config file.

applyEnv :: c -> IO cSource

Modify the config settings based on environment variables.

createPoolConfig :: c -> IO (PersistConfigPool c)Source

Create a new connection pool based on the given config settings.

runPool :: (MonadBaseControl IO m, MonadIO m) => c -> PersistConfigBackend c m a -> PersistConfigPool c -> m aSource

Run a database action by taking a connection from the pool.

Instances

class PersistField a whereSource

A value which can be marshalled to and from a PersistValue.

Methods

toPersistValue :: a -> PersistValueSource

fromPersistValue :: PersistValue -> Either Text aSource

Instances

class MonadIO m => PersistStore m whereSource

Associated Types

type PersistMonadBackend m Source

Methods

get :: (PersistMonadBackend m ~ PersistEntityBackend val, PersistEntity val) => Key val -> m (Maybe val)Source

Get a record by identifier, if available.

insert :: (PersistMonadBackend m ~ PersistEntityBackend val, PersistEntity val) => val -> m (Key val)Source

Create a new record in the database, returning an automatically created key (in SQL an auto-increment id).

insert_ :: (PersistMonadBackend m ~ PersistEntityBackend val, PersistEntity val) => val -> m ()Source

Same as insert, but doesn't return a Key.

insertMany :: (PersistMonadBackend m ~ PersistEntityBackend val, PersistEntity val) => [val] -> m [Key val]Source

Create multiple records in the database. SQL backends currently use the slow default implementation of mapM insert

insertKey :: (PersistMonadBackend m ~ PersistEntityBackend val, PersistEntity val) => Key val -> val -> m ()Source

Create a new record in the database using the given key.

repsert :: (PersistMonadBackend m ~ PersistEntityBackend val, PersistEntity val) => Key val -> val -> m ()Source

Put the record in the database with the given key. Unlike replace, if a record with the given key does not exist then a new record will be inserted.

replace :: (PersistMonadBackend m ~ PersistEntityBackend val, PersistEntity val) => Key val -> val -> m ()Source

Replace the record in the database with the given key. Note that the result is undefined if such record does not exist, so you must use 'insertKey or repsert in these cases.

delete :: (PersistMonadBackend m ~ PersistEntityBackend val, PersistEntity val) => Key val -> m ()Source

Delete a specific record by identifier. Does nothing if record does not exist.

Instances