def fix_stddev_function_name(self, compiler, connection):
    """
    Fix function names to 'STDEV' or 'STDEVP' as used by mssql
    """
    function = 'STDEV'
    if self.function == 'STDDEV_POP':
        function = 'STDEVP'
    return self.as_sql(compiler, connection, function=function)