fix output type for DateAdd() and DateSub() functions (#2609)

dolthub · Jul 31, 2024 · 6ad97cc · 6ad97cc
1 parent 5dedf37
commit 6ad97cc
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Showing 6 changed files with 314 additions and 49 deletions.
diff --git a/enginetest/enginetests.go b/enginetest/enginetests.go
@@ -5302,14 +5302,28 @@ func TestPrepared(t *testing.T, harness Harness) {
 		},
 		{
 			Query:    "SELECT DATE_ADD(TIMESTAMP(?), INTERVAL 1 DAY);",
-			Expected: []sql.Row{{time.Date(2022, time.October, 27, 13, 14, 15, 0, time.UTC)}},
+			Expected: []sql.Row{{"2022-10-27 13:14:15"}},
+			Bindings: map[string]*query.BindVariable{
+				"v1": mustBuildBindVariable(time.Date(2022, time.October, 26, 13, 14, 15, 0, time.UTC)),
+			},
+		},
+		{
+			Query:    "SELECT DATE_ADD(TIMESTAMP(?), INTERVAL 1 DAY);",
+			Expected: []sql.Row{{"2022-10-27 13:14:15"}},
 			Bindings: map[string]*query.BindVariable{
 				"v1": mustBuildBindVariable("2022-10-26 13:14:15"),
 			},
 		},
 		{
 			Query:    "SELECT DATE_ADD(?, INTERVAL 1 DAY);",
-			Expected: []sql.Row{{time.Date(2022, time.October, 27, 13, 14, 15, 0, time.UTC)}},
+			Expected: []sql.Row{{"2022-10-27 13:14:15"}},
+			Bindings: map[string]*query.BindVariable{
+				"v1": mustBuildBindVariable(time.Date(2022, time.October, 26, 13, 14, 15, 0, time.UTC)),
+			},
+		},
+		{
+			Query:    "SELECT DATE_ADD(?, INTERVAL 1 DAY);",
+			Expected: []sql.Row{{"2022-10-27 13:14:15"}},
 			Bindings: map[string]*query.BindVariable{
 				"v1": mustBuildBindVariable("2022-10-26 13:14:15"),
 			},

diff --git a/enginetest/queries/queries.go b/enginetest/queries/queries.go
@@ -6309,7 +6309,7 @@ Select * from (
 	},
 	{
 		Query:    "SELECT DATE_ADD('2018-05-02', INTERVAL 1 day)",
-		Expected: []sql.Row{{time.Date(2018, time.May, 3, 0, 0, 0, 0, time.UTC)}},
+		Expected: []sql.Row{{"2018-05-03"}},
 	},
 	{
 		Query:    "SELECT DATE_ADD(DATE('2018-05-02'), INTERVAL 1 day)",
@@ -6321,7 +6321,7 @@ Select * from (
 	},
 	{
 		Query:    "SELECT DATE_SUB('2018-05-02', INTERVAL 1 DAY)",
-		Expected: []sql.Row{{time.Date(2018, time.May, 1, 0, 0, 0, 0, time.UTC)}},
+		Expected: []sql.Row{{"2018-05-01"}},
 	},
 	{
 		Query:    "SELECT DATE_SUB(DATE('2018-05-02'), INTERVAL 1 DAY)",

diff --git a/sql/expression/function/date.go b/sql/expression/function/date.go
@@ -132,20 +132,43 @@ func (d *DateAdd) Eval(ctx *sql.Context, row sql.Row) (interface{}, error) {
 		return nil, nil
 	}
 
-	date, _, err = types.DatetimeMaxPrecision.Convert(date)
+	var dateVal interface{}
+	dateVal, _, err = types.DatetimeMaxPrecision.Convert(date)
 	if err != nil {
 		ctx.Warn(1292, err.Error())
 		return nil, nil
 	}
 
 	// return appropriate type
-	res := types.ValidateTime(delta.Add(date.(time.Time)))
+	res := types.ValidateTime(delta.Add(dateVal.(time.Time)))
+	if res == nil {
+		return nil, nil
+	}
+
 	resType := d.Type()
 	if types.IsText(resType) {
-		return res, nil
+		// If the input is a properly formatted date/datetime string, the output should also be a string
+		if dateStr, isStr := date.(string); isStr {
+			if res.(time.Time).Nanosecond() > 0 {
+				return res.(time.Time).Format(sql.DatetimeLayoutNoTrim), nil
+			}
+			if isHmsInterval(d.Interval) {
+				return res.(time.Time).Format(sql.TimestampDatetimeLayout), nil
+			}
+			for _, layout := range types.DateOnlyLayouts {
+				if _, pErr := time.Parse(layout, dateStr); pErr != nil {
+					continue
+				}
+				return res.(time.Time).Format(sql.DateLayout), nil
+			}
+		}
 	}
+
 	ret, _, err := resType.Convert(res)
-	return ret, err
+	if err != nil {
+		return nil, err
+	}
+	return ret, nil
 }
 
 func (d *DateAdd) String() string {
@@ -256,20 +279,43 @@ func (d *DateSub) Eval(ctx *sql.Context, row sql.Row) (interface{}, error) {
 		return nil, nil
 	}
 
-	date, _, err = types.DatetimeMaxPrecision.Convert(date)
+	var dateVal interface{}
+	dateVal, _, err = types.DatetimeMaxPrecision.Convert(date)
 	if err != nil {
 		ctx.Warn(1292, err.Error())
 		return nil, nil
 	}
 
 	// return appropriate type
-	res := types.ValidateTime(delta.Sub(date.(time.Time)))
+	res := types.ValidateTime(delta.Sub(dateVal.(time.Time)))
+	if res == nil {
+		return nil, nil
+	}
+
 	resType := d.Type()
 	if types.IsText(resType) {
-		return res, nil
+		// If the input is a properly formatted date/datetime string, the output should also be a string
+		if dateStr, isStr := date.(string); isStr {
+			if res.(time.Time).Nanosecond() > 0 {
+				return res.(time.Time).Format(sql.DatetimeLayoutNoTrim), nil
+			}
+			if isHmsInterval(d.Interval) {
+				return res.(time.Time).Format(sql.TimestampDatetimeLayout), nil
+			}
+			for _, layout := range types.DateOnlyLayouts {
+				if _, pErr := time.Parse(layout, dateStr); pErr != nil {
+					continue
+				}
+				return res.(time.Time).Format(sql.DateLayout), nil
+			}
+		}
 	}
+
 	ret, _, err := resType.Convert(res)
-	return ret, err
+	if err != nil {
+		return nil, err
+	}
+	return ret, nil
 }
 
 func (d *DateSub) String() string {
@@ -734,6 +780,20 @@ func (c CurrDate) WithChildren(children ...sql.Expression) (sql.Expression, erro
 	return NoArgFuncWithChildren(c, children)
 }
 
+func isYmdInterval(interval *expression.Interval) bool {
+	return strings.Contains(interval.Unit, "YEAR") ||
+		strings.Contains(interval.Unit, "QUARTER") ||
+		strings.Contains(interval.Unit, "MONTH") ||
+		strings.Contains(interval.Unit, "WEEK") ||
+		strings.Contains(interval.Unit, "DAY")
+}
+
+func isHmsInterval(interval *expression.Interval) bool {
+	return strings.Contains(interval.Unit, "HOUR") ||
+		strings.Contains(interval.Unit, "MINUTE") ||
+		strings.Contains(interval.Unit, "SECOND")
+}
+
 // Determines the return type of a DateAdd/DateSub expression
 // Logic is based on https://dev.mysql.com/doc/refman/8.0/en/date-and-time-functions.html#function_date-add
 func dateOffsetType(input sql.Expression, interval *expression.Interval) sql.Type {
@@ -747,31 +807,22 @@ func dateOffsetType(input sql.Expression, interval *expression.Interval) sql.Typ
 		return types.Null
 	}
 
+	if types.IsDatetimeType(inputType) || types.IsTimestampType(inputType) {
+		return types.DatetimeMaxPrecision
+	}
+
 	// set type flags
 	isInputDate := inputType == types.Date
 	isInputTime := inputType == types.Time
-	isInputDatetime := types.IsDatetimeType(inputType) || types.IsTimestampType(inputType)
-
-	// result is Datetime if expression is Datetime or Timestamp
-	if isInputDatetime {
-		return types.DatetimeMaxPrecision
-	}
 
 	// determine what kind of interval we're dealing with
-	isYmdInterval := strings.Contains(interval.Unit, "YEAR") ||
-		strings.Contains(interval.Unit, "QUARTER") ||
-		strings.Contains(interval.Unit, "MONTH") ||
-		strings.Contains(interval.Unit, "WEEK") ||
-		strings.Contains(interval.Unit, "DAY")
-
-	isHmsInterval := strings.Contains(interval.Unit, "HOUR") ||
-		strings.Contains(interval.Unit, "MINUTE") ||
-		strings.Contains(interval.Unit, "SECOND")
-	isMixedInterval := isYmdInterval && isHmsInterval
+	isYmd := isYmdInterval(interval)
+	isHms := isHmsInterval(interval)
+	isMixed := isYmd && isHms
 
 	// handle input of Date type
 	if isInputDate {
-		if isHmsInterval || isMixedInterval {
+		if isHms || isMixed {
 			// if interval contains time components, result is Datetime
 			return types.DatetimeMaxPrecision
 		} else {
@@ -782,7 +833,7 @@ func dateOffsetType(input sql.Expression, interval *expression.Interval) sql.Typ
 
 	// handle input of Time type
 	if isInputTime {
-		if isYmdInterval || isMixedInterval {
+		if isYmd || isMixed {
 			// if interval contains date components, result is Datetime
 			return types.DatetimeMaxPrecision
 		} else {
@@ -793,7 +844,7 @@ func dateOffsetType(input sql.Expression, interval *expression.Interval) sql.Typ
 
 	// handle dynamic input type
 	if types.IsDeferredType(inputType) {
-		if isYmdInterval && !isHmsInterval {
+		if isYmd && !isHms {
 			// if interval contains only date components, result is Date
 			return types.Date
 		} else {