Database.PostgreSQL.PQTypes.Class

Documentation

class (Applicative m, Monad m) => MonadDB m where

Methods

runQuery :: IsSQL sql => sql -> m Int

Run SQL query and return number of affected/returned rows. Note that for a given connection, only one thread may be executing runQuery at a given time. If simultaneous call is made from another thread, it will block until currently running runQuery finishes.

getLastQuery :: m SomeSQL

Get last SQL query that was executed.

getConnectionStats :: m ConnectionStats

Get current connection statistics.

getQueryResult :: m (Maybe QueryResult)

Get current query result.

clearQueryResult :: m ()

Clear current query result.

getTransactionSettings :: m TransactionSettings

Get current transaction settings.

setTransactionSettings :: TransactionSettings -> m ()

Set transaction settings to supplied ones. Note that it won't change any properties of currently running transaction, only the subsequent ones.

foldlM :: FromRow row => (acc -> row -> m acc) -> acc -> m acc

Fold the result set of rows from left to right.

foldrM :: FromRow row => (row -> acc -> m acc) -> acc -> m acc

Fold the result set of rows from right to left.

withNewConnection :: m a -> m a

Execute supplied monadic action with new connection using current connection source and transaction settings.

Particularly useful when you want to spawn a new thread, but do not want the connection in child thread to be shared with the parent one.

Instances

(Applicative (t m), Monad (t m), MonadTrans t, MonadTransControl t, MonadDB m) => MonadDB (t m)

MonadDB m => MonadDB (ListT m)

MonadDB m => MonadDB (MaybeT m)

MonadDB m => MonadDB (IdentityT m)

(MonadBase IO m, MonadMask m) => MonadDB (DBT m)

(Error e, MonadDB m) => MonadDB (ErrorT e m)

MonadDB m => MonadDB (ReaderT r m)

MonadDB m => MonadDB (StateT s m)

MonadDB m => MonadDB (StateT s m)

(Monoid w, MonadDB m) => MonadDB (WriterT w m)

(Monoid w, MonadDB m) => MonadDB (WriterT w m)

(Monoid w, MonadDB m) => MonadDB (RWST r w s m)

(Monoid w, MonadDB m) => MonadDB (RWST r w s m)