builtin: add quarter built-in function

expression/builtin_time.go

@@ -1729,7 +1729,35 @@ type builtinQuarterSig struct {
 
 // See https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_quarter
 func (b *builtinQuarterSig) eval(row []types.Datum) (d types.Datum, err error) {
-	return d, errFunctionNotExists.GenByArgs("QUARTER")
+	args, err := b.evalArgs(row)
+	if err != nil {
+		return types.Datum{}, errors.Trace(err)
+	}
+
+	d, err = builtinMonth(args, b.ctx)
+	if err != nil || d.IsNull() {
+		return d, errors.Trace(err)
+	}
+
+	mon := int(d.GetInt64())
+	switch mon {
+	case 0:
+		// An undocumented behavior of the mysql implementation
+		d.SetInt64(0)
+	case 1, 2, 3:
+		d.SetInt64(1)
+	case 4, 5, 6:
+		d.SetInt64(2)
+	case 7, 8, 9:
+		d.SetInt64(3)
+	case 10, 11, 12:
+		d.SetInt64(4)
+	default:
+		d.SetNull()
+		return d, errors.Errorf("no quarter for invalid month: %d.", mon)
+	}
+
+	return d, nil
 }
 
 type secToTimeFunctionClass struct {

expression/builtin_time_test.go

@@ -1013,3 +1013,39 @@ func (s *testEvaluatorSuite) TestTimestamp(c *C) {
 	c.Assert(err, IsNil)
 	c.Assert(d.Kind(), Equals, types.KindNull)
 }
+
+func (s *testEvaluatorSuite) TestQuarter(c *C) {
+	tests := []struct {
+		t      string
+		expect int64
+	}{
+		// Test case from https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_quarter
+		{"2008-04-01", 2},
+		// Test case for boundary values
+		{"2008-01-01", 1},
+		{"2008-03-31", 1},
+		{"2008-06-30", 2},
+		{"2008-07-01", 3},
+		{"2008-09-30", 3},
+		{"2008-10-01", 4},
+		{"2008-12-31", 4},
+		// Test case for month 0
+		{"2008-00-01", 0},
+	}
+	fc := funcs["quarter"]
+	for _, test := range tests {
+		arg := types.NewStringDatum(test.t)
+		f, err := fc.getFunction(datumsToConstants([]types.Datum{arg}), s.ctx)
+		c.Assert(err, IsNil)
+		result, err := f.eval(nil)
+		c.Assert(err, IsNil)
+		c.Assert(result.GetInt64(), Equals, test.expect)
+	}
+
+	// test invalid input
+	argInvalid := types.NewStringDatum("2008-13-01")
+	f, err := fc.getFunction(datumsToConstants([]types.Datum{argInvalid}), s.ctx)
+	c.Assert(err, IsNil)
+	result, err := f.eval(nil)
+	c.Assert(result.IsNull(), IsTrue)
+}

plan/typeinferer.go

@@ -359,7 +359,7 @@ func (v *typeInferrer) handleFuncCallExpr(x *ast.FuncCallExpr) {
 		tp = types.NewFieldType(mysql.TypeDatetime)
 	case "microsecond", "second", "minute", "hour", "day", "week", "month", "year",
 		"dayofweek", "dayofmonth", "dayofyear", "weekday", "weekofyear", "yearweek", "datediff",
-		"found_rows", "length", "extract", "locate", "unix_timestamp":
+		"found_rows", "length", "extract", "locate", "unix_timestamp", "quarter":
 		tp = types.NewFieldType(mysql.TypeLonglong)
 	case "now", "sysdate", "current_timestamp", "utc_timestamp":
 		tp = types.NewFieldType(mysql.TypeDatetime)

plan/typeinferer_test.go

@@ -156,6 +156,7 @@ func (ts *testTypeInferrerSuite) TestInferType(c *C) {
 		{"day('2009-12-31 23:59:59.000010')", mysql.TypeLonglong, charset.CharsetBin},
 		{"week('2009-12-31 23:59:59.000010')", mysql.TypeLonglong, charset.CharsetBin},
 		{"month('2009-12-31 23:59:59.000010')", mysql.TypeLonglong, charset.CharsetBin},
+		{"quarter('2009-12-31 23:59:59.000010')", mysql.TypeLonglong, charset.CharsetBin},
 		{"year('2009-12-31 23:59:59.000010')", mysql.TypeLonglong, charset.CharsetBin},
 		{"dayofweek('2009-12-31 23:59:59.000010')", mysql.TypeLonglong, charset.CharsetBin},
 		{"dayofmonth('2009-12-31 23:59:59.000010')", mysql.TypeLonglong, charset.CharsetBin},