Safe Haskell	None
Language	Haskell2010

Hasql.Transaction

Contents

Transaction monad

Description

An API for declaration of transactions.

Synopsis

data Transaction a
condemn :: Transaction ()
sql :: ByteString -> Transaction ()
statement :: a -> Statement a b -> Transaction b

Transaction monad

data Transaction a Source #

A composable abstraction over the retryable transactions.

Executes multiple queries under the specified mode and isolation level, while automatically retrying the transaction in case of conflicts. Thus this abstraction closely reproduces the behaviour of STM.

Instances

Instances details

Monad Transaction Source #
Instance details Defined in Hasql.Transaction.Private.Transaction Methods (>>=) :: Transaction a -> (a -> Transaction b) -> Transaction b (>>) :: Transaction a -> Transaction b -> Transaction b return :: a -> Transaction a
Functor Transaction Source #
Instance details Defined in Hasql.Transaction.Private.Transaction Methods fmap :: (a -> b) -> Transaction a -> Transaction b (<$) :: a -> Transaction b -> Transaction a
Applicative Transaction Source #
Instance details Defined in Hasql.Transaction.Private.Transaction Methods pure :: a -> Transaction a (<>) :: Transaction (a -> b) -> Transaction a -> Transaction b liftA2 :: (a -> b -> c) -> Transaction a -> Transaction b -> Transaction c (>) :: Transaction a -> Transaction b -> Transaction b (<*) :: Transaction a -> Transaction b -> Transaction a
Semigroup a => Semigroup (Transaction a) Source #
Instance details Defined in Hasql.Transaction.Private.Transaction Methods (<>) :: Transaction a -> Transaction a -> Transaction a sconcat :: NonEmpty (Transaction a) -> Transaction a stimes :: Integral b => b -> Transaction a -> Transaction a
Monoid a => Monoid (Transaction a) Source #
Instance details Defined in Hasql.Transaction.Private.Transaction Methods mempty :: Transaction a mappend :: Transaction a -> Transaction a -> Transaction a mconcat :: [Transaction a] -> Transaction a

condemn :: Transaction () Source #

Cause transaction to eventually roll back.

sql :: ByteString -> Transaction () Source #

Possibly a multi-statement query, which however cannot be parameterized or prepared, nor can any results of it be collected.

statement :: a -> Statement a b -> Transaction b Source #

Parameters and a specification of the parametric query to apply them to.