tablecodec,mysql, util: mysql TypeDuration Fsp (pingcap#3499)

Fixed RoundError issue pingcap#3471
Bug Cause:
1. when deserialize mysqlDuration, the Fsp is setted with 0 instead of the Fsp from column information.
2. the default decimal for column with TypeDuration is 0.

executor/executor_test.go

@@ -835,6 +835,12 @@ func (s *testSuite) TestBuiltin(c *C) {
 	result.Check(testkit.Rows("11:11:11"))
 	result = tk.MustQuery("select * from t where a > cast(2 as decimal)")
 	result.Check(testkit.Rows("3 2"))
+	// fixed issue #3471
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t(a time(6));")
+	tk.MustExec("insert into t value('12:59:59.999999')")
+	result = tk.MustQuery("select cast(a as signed) from t")
+	result.Check(testkit.Rows("130000"))
 
 	// test unhex and hex
 	result = tk.MustQuery("select unhex('4D7953514C')")
@@ -1176,9 +1182,9 @@ func (s *testSuite) TestDatumXAPI(c *C) {
 	tk.MustExec("insert t values ('11:11:12', '11:11:12')")
 	tk.MustExec("insert t values ('11:11:13', '11:11:13')")
 	result = tk.MustQuery("select * from t where a > '11:11:11.5'")
-	result.Check(testkit.Rows("11:11:12 11:11:12", "11:11:13 11:11:13"))
+	result.Check(testkit.Rows("11:11:12.000 11:11:12", "11:11:13.000 11:11:13"))
 	result = tk.MustQuery("select * from t where b > '11:11:11.5'")
-	result.Check(testkit.Rows("11:11:12 11:11:12", "11:11:13 11:11:13"))
+	result.Check(testkit.Rows("11:11:12.000 11:11:12", "11:11:13.000 11:11:13"))
 }
 
 func (s *testSuite) TestSQLMode(c *C) {

mysql/util.go

@@ -47,7 +47,7 @@ func GetDefaultDecimal(tp byte) int {
 	case TypeNewDecimal:
 		// See https://dev.mysql.com/doc/refman/5.7/en/fixed-point-types.html
 		return 0
-	case TypeDatetime:
+	case TypeDatetime, TypeDuration:
 		return 0
 	default:
 		//TODO: Add more types.

tablecodec/tablecodec.go

@@ -421,8 +421,8 @@ func unflatten(datum types.Datum, ft *types.FieldType, loc *time.Location) (type
 		}
 		datum.SetMysqlTime(t)
 		return datum, nil
-	case mysql.TypeDuration:
-		dur := types.Duration{Duration: time.Duration(datum.GetInt64())}
+	case mysql.TypeDuration: //duration should read fsp from column meta data
+		dur := types.Duration{Duration: time.Duration(datum.GetInt64()), Fsp: ft.Decimal}
 		datum.SetValue(dur)
 		return datum, nil
 	case mysql.TypeEnum:

tablecodec/tablecodec_test.go

@@ -143,16 +143,22 @@ func (s *testTableCodecSuite) TestTimeCodec(c *C) {
 	c1 := &column{id: 1, tp: types.NewFieldType(mysql.TypeLonglong)}
 	c2 := &column{id: 2, tp: types.NewFieldType(mysql.TypeVarchar)}
 	c3 := &column{id: 3, tp: types.NewFieldType(mysql.TypeTimestamp)}
-	cols := []*column{c1, c2, c3}
+	c4 := &column{id: 4, tp: types.NewFieldType(mysql.TypeDuration)}
+	cols := []*column{c1, c2, c3, c4}
+	colLen := len(cols)
 
-	row := make([]types.Datum, 3)
+	row := make([]types.Datum, colLen)
 	row[0] = types.NewIntDatum(100)
 	row[1] = types.NewBytesDatum([]byte("abc"))
 	ts, err := types.ParseTimestamp("2016-06-23 11:30:45")
 	c.Assert(err, IsNil)
 	row[2] = types.NewDatum(ts)
+	du, err := types.ParseDuration("12:59:59.999999", 6)
+	c.Assert(err, IsNil)
+	row[3] = types.NewDatum(du)
+
 	// Encode
-	colIDs := make([]int64, 0, 3)
+	colIDs := make([]int64, 0, colLen)
 	for _, col := range cols {
 		colIDs = append(colIDs, col.id)
 	}
@@ -161,14 +167,14 @@ func (s *testTableCodecSuite) TestTimeCodec(c *C) {
 	c.Assert(bs, NotNil)
 
 	// Decode
-	colMap := make(map[int64]*types.FieldType, 3)
+	colMap := make(map[int64]*types.FieldType, colLen)
 	for _, col := range cols {
 		colMap[col.id] = col.tp
 	}
 	r, err := DecodeRow(bs, colMap, time.Local)
 	c.Assert(err, IsNil)
 	c.Assert(r, NotNil)
-	c.Assert(r, HasLen, 3)
+	c.Assert(r, HasLen, colLen)
 	sc := new(variable.StatementContext)
 	// Compare decoded row and original row
 	for i, col := range cols {

util/types/field_type.go

@@ -127,7 +127,7 @@ func (ft *FieldType) CompactStr() string {
 			es = append(es, e)
 		}
 		suffix = fmt.Sprintf("('%s')", strings.Join(es, "','"))
-	case mysql.TypeTimestamp, mysql.TypeDatetime, mysql.TypeDate:
+	case mysql.TypeTimestamp, mysql.TypeDatetime, mysql.TypeDate, mysql.TypeDuration:
 		if ft.Decimal != UnspecifiedLength && ft.Decimal != 0 {
 			suffix = fmt.Sprintf("(%d)", ft.Decimal)
 		}