| Copyright | (c) Eitan Chatav 2019 |
|---|---|
| Maintainer | [email protected] |
| Stability | experimental |
| Safe Haskell | None |
| Language | Haskell2010 |
Squeal.PostgreSQL.Session.Result
Description
Get values from a Result.
Synopsis
- data Result y where
- getRow :: MonadIO io => Row -> Result y -> io y
- firstRow :: MonadIO io => Result y -> io (Maybe y)
- getRows :: MonadIO io => Result y -> io [y]
- nextRow :: MonadIO io => Row -> Result y -> Row -> io (Maybe (Row, y))
- cmdStatus :: MonadIO io => Result y -> io Text
- cmdTuples :: MonadIO io => Result y -> io (Maybe Row)
- ntuples :: MonadIO io => Result y -> io Row
- nfields :: MonadIO io => Result y -> io Column
- resultStatus :: MonadIO io => Result y -> io ExecStatus
- okResult :: MonadIO io => Result y -> io ()
- resultErrorMessage :: MonadIO io => Result y -> io (Maybe ByteString)
- resultErrorCode :: MonadIO io => Result y -> io (Maybe ByteString)
- liftResult :: MonadIO io => (Result -> IO x) -> Result y -> io x
Documentation
getRow :: MonadIO io => Row -> Result y -> io y Source #
Get a row corresponding to a given row number from a Result,
throwing an exception if the row number is out of bounds.
firstRow :: MonadIO io => Result y -> io (Maybe y) Source #
Get the first row if possible from a Result.
cmdStatus :: MonadIO io => Result y -> io Text Source #
Returns the command status tag from the SQL command
that generated the Result.
Commonly this is just the name of the command,
but it might include additional data such as the number of rows processed.
cmdTuples :: MonadIO io => Result y -> io (Maybe Row) Source #
Returns the number of rows affected by the SQL command.
This function returns Just the number of
rows affected by the SQL statement that generated the Result.
This function can only be used following the execution of a
SELECT, CREATE TABLE AS, INSERT, UPDATE, DELETE, MOVE, FETCH,
or COPY statement,or an EXECUTE of a prepared query that
contains an INSERT, UPDATE, or DELETE statement.
If the command that generated the PGresult was anything else,
cmdTuples returns Nothing.
ntuples :: MonadIO io => Result y -> io Row Source #
Returns the number of rows (tuples) in the query result.
nfields :: MonadIO io => Result y -> io Column Source #
Returns the number of columns (fields) in the query result.
resultStatus :: MonadIO io => Result y -> io ExecStatus Source #
Returns the result status of the command.
okResult :: MonadIO io => Result y -> io () Source #
Check if a Result's status is either CommandOk
or TuplesOk otherwise throw a SQLException.
resultErrorMessage :: MonadIO io => Result y -> io (Maybe ByteString) Source #
Returns the error message most recently generated by an operation on the connection.
resultErrorCode :: MonadIO io => Result y -> io (Maybe ByteString) Source #
Returns the error code most recently generated by an operation on the connection.