Database.PostgreSQL.Transaction

Documentation

type PGTransaction = PGTransactionT IO

runPGTransactionT :: MonadBaseControl IO m => PGTransactionT m a -> Connection -> m a

runPGTransactionT' :: MonadBaseControl IO m => IsolationLevel -> PGTransactionT m a -> Connection -> m a

runPGTransactionIO :: MonadIO m => PGTransaction a -> Connection -> m a

Convenience function when there are no embedded monadic effects, only IO.

query :: (ToRow input, FromRow output, MonadIO m) => input -> Query -> PGTransactionT m [output]

Issue an SQL query, taking a ToRow input and yielding FromRow outputs. Please note that the parameter order is different from that in the parent postgresql-simple library; this is an intentional choice to improve the aesthetics when using the SQL quasiquoter (making the query parameters come first means that there is more room for the query string).

query_ :: (FromRow output, MonadIO m) => Query -> PGTransactionT m [output]

As query, but for queries that take no arguments.

execute :: (ToRow input, MonadIO m) => input -> Query -> PGTransactionT m Int64

Run a single SQL action and return success.

executeOne :: (ToRow input, MonadIO m) => input -> Query -> PGTransactionT m Bool

Run a statement and return True if only a single record was modified.

executeMany :: (ToRow input, MonadIO m) => [input] -> Query -> PGTransactionT m Int64

returning :: (ToRow input, FromRow output, MonadIO m) => [input] -> Query -> PGTransactionT m [output]

queryHead :: (ToRow input, FromRow output, MonadIO m) => input -> Query -> PGTransactionT m (Maybe output)

Run a query and return Just the first result found or Nothing.

queryOnly :: (ToRow input, FromField f, MonadIO m) => input -> Query -> PGTransactionT m (Maybe f)

Lookup a single FromField value. This takes care of handling Only for you.

formatQuery :: (ToRow input, MonadIO m) => input -> Query -> PGTransactionT m Query