__init__.py 文件源码

def ping_connection(connection, branch):
    if branch:
        # Don't ping sub-connections
        return

    try:
        # Test the connection
        connection.scalar(select([1]))
    except exc.DBAPIError as e:
        if e.connection_invalidated:
            # Establish a new connection
            connection.scalar(select([1]))
        else:
            raise