}

func handleDateAdd(r Record, d *DateAddFunc, tableAlias string) (*Value, error) {
	q, err := d.Quantity.evalNode(r, tableAlias)
	if err != nil {
		return nil, err
	}
	inferTypeForArithOp(q)
	qty, ok := q.ToFloat()
	if !ok {
		return nil, fmt.Errorf("QUANTITY must be a numeric argument to %s()", sqlFnDateAdd)
	}

	ts, err := d.Timestamp.evalNode(r, tableAlias)
	if err != nil {

type DateAddFunc struct {
	DatePart  string       `parser:" \"DATE_ADD\" \"(\" @( \"YEAR\":Timeword | \"MONTH\":Timeword | \"DAY\":Timeword | \"HOUR\":Timeword | \"MINUTE\":Timeword | \"SECOND\":Timeword ) \",\""`
	Quantity  *Operand     `parser:" @@ \",\""`
	Timestamp *PrimaryTerm `parser:" @@ \")\""`
}

// DateDiffFunc represents the DATE_DIFF function
type DateDiffFunc struct {

	switch funcName {
	case sqlFnCast:
		return e.Cast.Expr.analyze(s)

	case sqlFnExtract:
		return e.Extract.From.analyze(s)

	case sqlFnDateAdd:
		result.combine(e.DateAdd.Quantity.analyze(s))
		result.combine(e.DateAdd.Timestamp.analyze(s))
		return result

	case sqlFnDateDiff:
		result.combine(e.DateDiff.Timestamp1.analyze(s))
		result.combine(e.DateDiff.Timestamp2.analyze(s))