table,tablecodec,util/types: make it possible to read empty enum value (

pingcap#3664)
kirk91 · Jul 12, 2017 · a0dfa04 · a0dfa04
1 parent 9e6cc3a
commit a0dfa04
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Showing 6 changed files with 37 additions and 8 deletions.
diff --git a/executor/executor_test.go b/executor/executor_test.go
@@ -1984,3 +1984,27 @@ func (s *testSuite) TestFuncREPEAT(c *C) {
 	r = tk.MustQuery("SELECT REPEAT(a, 16777217), REPEAT(b, 16777217), REPEAT(c, 16777217), REPEAT(d, 16777217), REPEAT(e, 16777217), REPEAT(f, 16777217) FROM table_string;")
 	r.Check(testkit.Rows("<nil> <nil> <nil> <nil> <nil> <nil>"))
 }
+
+func (s *testSuite) TestEmptyEnum(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	defer func() {
+		s.cleanEnv(c)
+		testleak.AfterTest(c)()
+	}()
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t (e enum('Y', 'N'))")
+	tk.MustExec("set sql_mode='STRICT_TRANS_TABLES'")
+	_, err := tk.Exec("insert into t values (0)")
+	c.Assert(terror.ErrorEqual(err, types.ErrTruncated), IsTrue)
+	_, err = tk.Exec("insert into t values ('abc')")
+	c.Assert(terror.ErrorEqual(err, types.ErrTruncated), IsTrue)
+
+	tk.MustExec("set sql_mode=''")
+	tk.MustExec("insert into t values (0)")
+	tk.MustQuery("select * from t").Check(testkit.Rows(""))
+	tk.MustExec("insert into t values ('abc')")
+	tk.MustQuery("select * from t").Check(testkit.Rows("", ""))
+	tk.MustExec("insert into t values (null)")
+	tk.MustQuery("select * from t").Check(testkit.Rows("", "", "<nil>"))
+}
diff --git a/table/column.go b/table/column.go
@@ -360,6 +360,8 @@ func GetZeroValue(col *model.ColumnInfo) types.Datum {
 		d.SetMysqlBit(types.Bit{Value: 0, Width: types.MinBitWidth})
 	case mysql.TypeSet:
 		d.SetMysqlSet(types.Set{})
+	case mysql.TypeEnum:
+		d.SetMysqlEnum(types.Enum{})
 	}
 	return d
 }
diff --git a/table/column_test.go b/table/column_test.go
@@ -173,6 +173,10 @@ func (s *testColumnSuite) TestGetZeroValue(c *C) {
 			types.NewFieldType(mysql.TypeSet),
 			types.NewDatum(types.Set{}),
 		},
+		{
+			types.NewFieldType(mysql.TypeEnum),
+			types.NewDatum(types.Enum{}),
+		},
 	}
 	sc := new(variable.StatementContext)
 	for _, tt := range tests {

diff --git a/tablecodec/tablecodec.go b/tablecodec/tablecodec.go
@@ -416,10 +416,8 @@ func unflatten(datum types.Datum, ft *types.FieldType, loc *time.Location) (type
 		datum.SetValue(dur)
 		return datum, nil
 	case mysql.TypeEnum:
-		enum, err := types.ParseEnumValue(ft.Elems, datum.GetUint64())
-		if err != nil {
-			return datum, errors.Trace(err)
-		}
+		// ignore error deliberately, to read empty enum value.
+		enum, _ := types.ParseEnumValue(ft.Elems, datum.GetUint64())
 		datum.SetValue(enum)
 		return datum, nil
 	case mysql.TypeSet:

diff --git a/util/types/convert_test.go b/util/types/convert_test.go
@@ -276,8 +276,9 @@ func (s *testTypeConvertSuite) TestConvertType(c *C) {
 	c.Assert(v, DeepEquals, Enum{Name: "b", Value: 2})
 	_, err = Convert("d", ft)
 	c.Assert(err, NotNil)
-	_, err = Convert(4, ft)
-	c.Assert(err, NotNil)
+	v, err = Convert(4, ft)
+	c.Assert(terror.ErrorEqual(err, ErrTruncated), IsTrue)
+	c.Assert(v, DeepEquals, Enum{})
 
 	ft = NewFieldType(mysql.TypeSet)
 	ft.Elems = []string{"a", "b", "c"}

diff --git a/util/types/datum.go b/util/types/datum.go
@@ -1201,10 +1201,10 @@ func (d *Datum) convertToMysqlEnum(sc *variable.StatementContext, target *FieldT
 		e, err = ParseEnumValue(target.Elems, uintDatum.GetUint64())
 	}
 	if err != nil {
-		return invalidConv(d, target.Tp)
+		err = errors.Wrap(err, ErrTruncated)
 	}
 	ret.SetValue(e)
-	return ret, nil
+	return ret, err
 }
 
 func (d *Datum) convertToMysqlSet(sc *variable.StatementContext, target *FieldType) (Datum, error) {