}
		length = int(lenInt)
		if length < 0 {
			err := fmt.Errorf("Negative length argument in %s", sqlFnSubstring)
			return nil, errIncorrectSQLFunctionArgumentType(err)
		}
	}

	res, err := evalSQLSubstring(s, int(startIdx), length)
	return FromString(res), err
}

func handleSQLTrim(r Record, e *TrimFunc, tableAlias string) (res *Value, err error) {
	chars := ""
	ok := false
	if e.TrimChars != nil {