Function timeFromDatumForComparison

pkg/sql/sem/tree/datum.go:2202–2228

timeFromDatumForComparison gets the time from a datum object to use strictly for comparison usage.

(ctx *EvalContext, d Datum)

// timeFromDatumForComparison gets the time from a datum object to use
// strictly for comparison usage.
func timeFromDatumForComparison(ctx *EvalContext, d Datum) (time.Time, bool) {
	d = UnwrapDatum(ctx, d)
	switch t := d.(type) {
	case *DDate:
		ts, err := MakeDTimestampTZFromDate(ctx.GetLocation(), t)
		if err != nil {
			return time.Time{}, false
		}
		return ts.Time, true
	case *DTimestampTZ:
		return t.Time, true
	case *DTimestamp:
		// Normalize to the timezone of the context.
		_, zoneOffset := t.Time.In(ctx.GetLocation()).Zone()
		ts := t.Time.In(ctx.GetLocation()).Add(-time.Duration(zoneOffset) * time.Second)
		return ts, true
	case *DTime:
		// Normalize to the timezone of the context.
		toTime := timeofday.TimeOfDay(*t).ToTime()
		_, zoneOffsetSecs := toTime.In(ctx.GetLocation()).Zone()
		return toTime.In(ctx.GetLocation()).Add(-time.Duration(zoneOffsetSecs) * time.Second), true
	case *DTimeTZ:
		return t.ToTime(), true
	default:
		return time.Time{}, false
	}
}

func compareTimestamps(ctx *EvalContext, l Datum, r Datum) int {
	lTime, lOk := timeFromDatumForComparison(ctx, l)