Database.PostgreSQL.Store.Errand

Documentation

data ErrandError

Error during errand

Constructors

NoResult

ExecError ExecStatus (Maybe ByteString)

ResultError ResultError

UnexpectedEmptyResult

UserError String

Instances

Eq ErrandError

Show ErrandError

type Errand = ReaderT Connection (ExceptT ErrandError IO)

An interaction with the database

runErrand :: Connection -> Errand a -> IO (Either ErrandError a)

Run an errand.

raiseErrandError :: ErrandError -> Errand a

Raise an error.

executeQuery :: Query -> Errand Result

Execute a query and return its result.

query :: Result a => Query -> Errand [a]

Execute a query and process its result set. It is essential that all fields required by the underlying result parser are present.

query_ :: Query -> Errand ()

Execute a query.