Hasql.Connection

This module provides a low-level effectful API dealing with the connections to the database.

Documentation

data Connection

A single connection to the database.

Instances

MonadReader Connection Session

Defined in Hasql.Session.Core

Methods

ask :: Session Connection

local :: (Connection -> Connection) -> Session a -> Session a

reader :: (Connection -> a) -> Session a

type ConnectionError = Maybe ByteString

Possible details of the connection acquistion error.

acquire :: Settings -> IO (Either ConnectionError Connection)

Acquire a connection using the provided settings encoded according to the PostgreSQL format.

release :: Connection -> IO ()

Release the connection.

type Settings = ByteString

All settings encoded in a single byte-string according to the PostgreSQL format.

settings :: ByteString -> Word16 -> ByteString -> ByteString -> ByteString -> Settings

Encode a host, a port, a user, a password and a database into the PostgreSQL settings byte-string.

withLibPQConnection :: Connection -> (Connection -> IO a) -> IO a

Execute an operation on the raw libpq Connection.

The access to the connection is exclusive.