Database.MonetDB.Mapi

Error handling

data MapiError

Some IO actions might throw MapiError.

Instances

Show MapiError

Methods

showsPrec :: Int -> MapiError -> ShowS

show :: MapiError -> String

showList :: [MapiError] -> ShowS

Exception MapiError

Methods

toException :: MapiError -> SomeException

fromException :: SomeException -> Maybe MapiError

displayException :: MapiError -> String

errorType :: MapiError -> ErrorType

data ErrorType

Error types that may occur within MonetDB.

Constructors

Default String

Timeout

Server String

Instances

Show ErrorType

Methods

showsPrec :: Int -> ErrorType -> ShowS

show :: ErrorType -> String

showList :: [ErrorType] -> ShowS

Connection parameters

data Lang

The language to be used for a connection.

Constructors

Sql

Mil

Mal

XQuery

data ConInfo

Constructors

ConInfo

Fields

• ciOptHost :: Maybe String
• ciOptPort :: Maybe Int
• ciUsername :: Maybe String
• ciPassword :: Maybe String
• ciDbName :: Database

emptyConInfo :: Database -> ConInfo

A ConInfo with all optional fields omitted.

defConInfo :: Database -> ConInfo

A ConInfo with common default settings, mostly for testing purposes.

Connection handling

newtype Connection

Constructors

Connection Mapi

connect :: ConInfo -> Lang -> IO Connection

It is strongly advised to use withConnection, which is exception-safe.

disconnect :: Connection -> IO ()

withConnection :: ConInfo -> Lang -> (Connection -> IO a) -> IO a

Opens a connection, runs the action and closes the connection, even when an exception has been thrown.

>>> withConnection (defConInfo "test") Mal $ \c -> quickQuery c "io.print(42, 23);"
[["42", "23"]]

Queries

quickQuery :: Connection -> String -> IO [[String]]

Run a query and fetch the result rows.

quickQuery_ :: Connection -> String -> IO ()