day function has been fixed

Author: angelamayxie

enginetest/queries/function_queries.go

@@ -1779,14 +1779,13 @@ var FunctionQueryTests = []QueryTest{
 		ExpectedWarningsCount: 1,
 	},
 	{
-		Query:                 "select day('0000-00-00')",
-		Expected:              []sql.Row{{nil}},
-		ExpectedWarning:       mysql.ERTruncatedWrongValue,
-		ExpectedWarningsCount: 1,
+		// This is not a valid time string in MySQL but we allow it
+		Query:    "select day('0000-00-00')",
+		Expected: []sql.Row{{0}},
 	},
 	{
 		Query:    "select day('0000-01-01')",
-		Expected: []sql.Row{{0}},
+		Expected: []sql.Row{{1}},
 	},
 	{
 		Query:                 "select dayname(0)",

sql/expression/function/time.go

@@ -546,7 +546,14 @@ func datePartFunc(fn func(time.Time) int) func(interface{}) interface{} {
 			return nil
 		}
 
-		return int32(fn(v.(time.Time)))
+		if vTime, ok := v.(time.Time); ok {
+			if vTime.Equal(types.ZeroTime) {
+				return 0
+			}
+
+			return int32(fn(vTime))
+		}
+		return nil
 	}
 }
 

sql/types/datetime.go

@@ -100,7 +100,7 @@ var (
 
 	// zeroTime is -0001-11-30 00:00:00 UTC which is the closest Go can get to 0000-00-00 00:00:00 without conflicting
 	// with a valid timestamp in MySQL
-	zeroTime = time.Date(0, 0, 0, 0, 0, 0, 0, time.UTC)
+	ZeroTime = time.Date(0, 0, 0, 0, 0, 0, 0, time.UTC)
 
 	// Date is a date with day, month and year.
 	Date = MustCreateDatetimeType(sqltypes.Date, 0)
@@ -223,8 +223,8 @@ func ConvertToTime(ctx context.Context, v interface{}, t datetimeType) (time.Tim
 		return time.Time{}, err
 	}
 
-	if res.Equal(zeroTime) {
-		return zeroTime, nil
+	if res.Equal(ZeroTime) {
+		return ZeroTime, nil
 	}
 
 	// Round the date to the precision of this type
@@ -276,103 +276,103 @@ func (t datetimeType) ConvertWithoutRangeCheck(ctx context.Context, v interface{
 	switch value := v.(type) {
 	case string:
 		if value == ZeroDateStr || value == ZeroTimestampDatetimeStr {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
 		// TODO: consider not using time.Parse if we want to match MySQL exactly ('2010-06-03 11:22.:.:.:.:' is a valid timestamp)
 		var parsed bool
 		res, parsed, err = parseDatetime(value)
 		if !parsed {
-			return zeroTime, ErrConvertingToTime.New(v)
+			return ZeroTime, ErrConvertingToTime.New(v)
 		}
 	case time.Time:
 		res = value.UTC()
 	// For most integer values, we just return an error (but MySQL is more lenient for some of these). A special case
 	// is zero values, which are important when converting from postgres defaults.
 	case int:
 		if value == 0 {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case int8:
 		if value == 0 {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case int16:
 		if value == 0 {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case int32:
 		if value == 0 {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case int64:
 		if value == 0 {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case uint:
 		if value == 0 {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case uint8:
 		if value == 0 {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case uint16:
 		if value == 0 {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case uint32:
 		if value == 0 {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case uint64:
 		if value == 0 {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case float32:
 		if value == 0 {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case float64:
 		if value == 0 {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case decimal.Decimal:
 		if value.IsZero() {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case decimal.NullDecimal:
 		if value.Valid && value.Decimal.IsZero() {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	case Timespan:
 		// when receiving TIME, MySQL fills in date with today
 		nowTimeStr := sql.Now().Format("2006-01-02")
 		nowTime, err := time.Parse("2006-01-02", nowTimeStr)
 		if err != nil {
-			return zeroTime, ErrConvertingToTime.New(v)
+			return ZeroTime, ErrConvertingToTime.New(v)
 		}
 		return nowTime.Add(value.AsTimeDuration()), nil
 	case bool:
 		if !value {
-			return zeroTime, nil
+			return ZeroTime, nil
 		}
-		return zeroTime, ErrConvertingToTime.New(v)
+		return ZeroTime, ErrConvertingToTime.New(v)
 	default:
-		return zeroTime, sql.ErrConvertToSQL.New(value, t)
+		return ZeroTime, sql.ErrConvertToSQL.New(value, t)
 	}
 
 	if t.baseType == sqltypes.Date {
@@ -458,21 +458,21 @@ func (t datetimeType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqltype
 	switch t.baseType {
 	case sqltypes.Date:
 		typ = sqltypes.Date
-		if vt.Equal(zeroTime) {
+		if vt.Equal(ZeroTime) {
 			val = vt.AppendFormat(dest, ZeroDateStr)
 		} else {
 			val = vt.AppendFormat(dest, sql.DateLayout)
 		}
 	case sqltypes.Datetime:
 		typ = sqltypes.Datetime
-		if vt.Equal(zeroTime) {
+		if vt.Equal(ZeroTime) {
 			val = vt.AppendFormat(dest, ZeroTimestampDatetimeStr)
 		} else {
 			val = vt.AppendFormat(dest, sql.TimestampDatetimeLayout)
 		}
 	case sqltypes.Timestamp:
 		typ = sqltypes.Timestamp
-		if vt.Equal(zeroTime) {
+		if vt.Equal(ZeroTime) {
 			val = vt.AppendFormat(dest, ZeroTimestampDatetimeStr)
 		} else {
 			val = vt.AppendFormat(dest, sql.TimestampDatetimeLayout)
@@ -535,7 +535,7 @@ func (t datetimeType) ValueType() reflect.Type {
 }
 
 func (t datetimeType) Zero() interface{} {
-	return zeroTime
+	return ZeroTime
 }
 
 // CollationCoercibility implements sql.CollationCoercible interface.