*: use FieldType.Decimal to control the decimal length of double valu…

…es to be shown in client (pingcap#4191)
Yui-Song · Aug 15, 2017 · 1dc7bbe · 1dc7bbe
1 parent a454c57
commit 1dc7bbe
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Showing 5 changed files with 38 additions and 22 deletions.
diff --git a/expression/builtin_math.go b/expression/builtin_math.go
@@ -1370,8 +1370,8 @@ func (c *piFunctionClass) getFunction(args []Expression, ctx context.Context) (b
 		return nil, errors.Trace(err)
 	}
 
-	bf.tp.Decimal = 15
-	bf.tp.Flen = 17
+	bf.tp.Decimal = 6
+	bf.tp.Flen = 8
 	sig = &builtinPISig{baseRealBuiltinFunc{bf}}
 	return sig.setSelf(sig), nil
 }

diff --git a/plan/typeinfer_test.go b/plan/typeinfer_test.go
@@ -344,7 +344,7 @@ func (s *testPlanSuite) createTestCase4MathFuncs() []typeInferTestCase {
 		{"exp(c_time)", mysql.TypeDouble, charset.CharsetBin, mysql.BinaryFlag, mysql.MaxRealWidth, types.UnspecifiedLength},
 		{"exp(c_timestamp)", mysql.TypeDouble, charset.CharsetBin, mysql.BinaryFlag, mysql.MaxRealWidth, types.UnspecifiedLength},
 		{"exp(c_binary)", mysql.TypeDouble, charset.CharsetBin, mysql.BinaryFlag, mysql.MaxRealWidth, types.UnspecifiedLength},
-		{"pi()", mysql.TypeDouble, charset.CharsetBin, mysql.BinaryFlag, 17, 15},
+		{"pi()", mysql.TypeDouble, charset.CharsetBin, mysql.BinaryFlag, 8, 6},
 		{"~c_int", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag | mysql.UnsignedFlag, mysql.MaxIntWidth, 0},
 		{"!c_int", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 1, 0},
 		{"c_int & c_int", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag | mysql.UnsignedFlag, mysql.MaxIntWidth, 0},

diff --git a/server/conn.go b/server/conn.go
@@ -783,7 +783,7 @@ func (cc *clientConn) writeResultset(rs ResultSet, binary bool, more bool) error
 					continue
 				}
 				var valData []byte
-				valData, err = dumpTextValue(columns[i].Type, value)
+				valData, err = dumpTextValue(columns[i], value)
 				if err != nil {
 					return errors.Trace(err)
 				}

diff --git a/server/util.go b/server/util.go
@@ -318,22 +318,22 @@ func dumpRowValuesBinary(alloc arena.Allocator, columns []*ColumnInfo, row []typ
 	return
 }
 
-func dumpTextValue(mysqlType uint8, value types.Datum) ([]byte, error) {
+func dumpTextValue(colInfo *ColumnInfo, value types.Datum) ([]byte, error) {
 	switch value.Kind() {
 	case types.KindInt64:
 		return strconv.AppendInt(nil, value.GetInt64(), 10), nil
 	case types.KindUint64:
 		return strconv.AppendUint(nil, value.GetUint64(), 10), nil
 	case types.KindFloat32:
 		prec := -1
-		if frac := value.Frac(); frac > 0 {
-			prec = frac
+		if colInfo.Decimal > 0 && int(colInfo.Decimal) != mysql.NotFixedDec {
+			prec = int(colInfo.Decimal)
 		}
 		return strconv.AppendFloat(nil, value.GetFloat64(), 'f', prec, 32), nil
 	case types.KindFloat64:
 		prec := -1
-		if frac := value.Frac(); frac > 0 {
-			prec = frac
+		if colInfo.Decimal > 0 && int(colInfo.Decimal) != mysql.NotFixedDec {
+			prec = int(colInfo.Decimal)
 		}
 		return strconv.AppendFloat(nil, value.GetFloat64(), 'f', prec, 64), nil
 	case types.KindString, types.KindBytes:

diff --git a/server/util_test.go b/server/util_test.go
@@ -52,37 +52,50 @@ func (s *testUtilSuite) TestDumpBinaryTime(c *C) {
 
 func (s *testUtilSuite) TestDumpTextValue(c *C) {
 	defer testleak.AfterTest(c)()
-	bs, err := dumpTextValue(mysql.TypeLonglong, types.NewIntDatum(10))
+
+	colInfo := &ColumnInfo{
+		Type:    mysql.TypeLonglong,
+		Decimal: mysql.NotFixedDec,
+	}
+	bs, err := dumpTextValue(colInfo, types.NewIntDatum(10))
 	c.Assert(err, IsNil)
 	c.Assert(string(bs), Equals, "10")
 
-	bs, err = dumpTextValue(mysql.TypeLonglong, types.NewUintDatum(11))
+	bs, err = dumpTextValue(colInfo, types.NewUintDatum(11))
 	c.Assert(err, IsNil)
 	c.Assert(string(bs), Equals, "11")
 
+	colInfo.Type = mysql.TypeFloat
+	colInfo.Decimal = 1
 	f32 := types.NewFloat32Datum(1.2)
-	bs, err = dumpTextValue(mysql.TypeDouble, f32)
+	bs, err = dumpTextValue(colInfo, f32)
 	c.Assert(err, IsNil)
 	c.Assert(string(bs), Equals, "1.2")
-	f32.SetFrac(2)
-	bs, err = dumpTextValue(mysql.TypeDouble, f32)
+
+	colInfo.Decimal = 2
+	bs, err = dumpTextValue(colInfo, f32)
 	c.Assert(err, IsNil)
 	c.Assert(string(bs), Equals, "1.20")
 
 	f64 := types.NewFloat64Datum(2.2)
-	bs, err = dumpTextValue(mysql.TypeDouble, f64)
+	colInfo.Type = mysql.TypeDouble
+	colInfo.Decimal = 1
+	bs, err = dumpTextValue(colInfo, f64)
 	c.Assert(err, IsNil)
 	c.Assert(string(bs), Equals, "2.2")
-	f64.SetFrac(2)
-	bs, err = dumpTextValue(mysql.TypeDouble, f64)
+
+	colInfo.Decimal = 2
+	bs, err = dumpTextValue(colInfo, f64)
 	c.Assert(err, IsNil)
 	c.Assert(string(bs), Equals, "2.20")
 
-	bs, err = dumpTextValue(mysql.TypeBlob, types.NewBytesDatum([]byte("foo")))
+	colInfo.Type = mysql.TypeBlob
+	bs, err = dumpTextValue(colInfo, types.NewBytesDatum([]byte("foo")))
 	c.Assert(err, IsNil)
 	c.Assert(string(bs), Equals, "foo")
 
-	bs, err = dumpTextValue(mysql.TypeVarchar, types.NewStringDatum("bar"))
+	colInfo.Type = mysql.TypeVarchar
+	bs, err = dumpTextValue(colInfo, types.NewStringDatum("bar"))
 	c.Assert(err, IsNil)
 	c.Assert(string(bs), Equals, "bar")
 
@@ -91,19 +104,22 @@ func (s *testUtilSuite) TestDumpTextValue(c *C) {
 	time, err := types.ParseTime("2017-01-05 23:59:59.575601", mysql.TypeDatetime, 0)
 	c.Assert(err, IsNil)
 	d.SetMysqlTime(time)
-	bs, err = dumpTextValue(mysql.TypeDatetime, d)
+	colInfo.Type = mysql.TypeDatetime
+	bs, err = dumpTextValue(colInfo, d)
 	c.Assert(err, IsNil)
 	c.Assert(string(bs), Equals, "2017-01-06 00:00:00")
 
 	duration, err := types.ParseDuration("11:30:45", 0)
 	c.Assert(err, IsNil)
 	d.SetMysqlDuration(duration)
-	bs, err = dumpTextValue(mysql.TypeDuration, d)
+	colInfo.Type = mysql.TypeDuration
+	bs, err = dumpTextValue(colInfo, d)
 	c.Assert(err, IsNil)
 	c.Assert(string(bs), Equals, "11:30:45")
 
 	d.SetMysqlDecimal(types.NewDecFromStringForTest("1.23"))
-	bs, err = dumpTextValue(mysql.TypeNewDecimal, d)
+	colInfo.Type = mysql.TypeNewDecimal
+	bs, err = dumpTextValue(colInfo, d)
 	c.Assert(err, IsNil)
 	c.Assert(string(bs), Equals, "1.23")
 }