ddl: year type should not has unsigned flag

ddl/ddl_api.go

@@ -366,7 +366,7 @@ func columnDefToCol(ctx sessionctx.Context, offset int, colDef *ast.ColumnDef) (
 	if col.Tp == mysql.TypeYear {
 		// For Year field, it's charset is binary but does not have binary flag.
 		col.Flag &= ^mysql.BinaryFlag
-		col.Flag |= mysql.UnsignedFlag | mysql.ZerofillFlag
+		col.Flag |= mysql.ZerofillFlag
 	}
 	err := checkDefaultValue(ctx, col, hasDefaultValue)
 	if err != nil {

ddl/ddl_db_test.go

@@ -1894,6 +1894,26 @@ func (s *testDBSuite) TestRebaseAutoID(c *C) {
 	s.testErrorCode(c, "alter table tidb.test2 add column b int auto_increment key, auto_increment=10;", tmysql.ErrUnknown)
 }
 
+func (s *testDBSuite) TestYearTypeCreateTable(c *C) {
+	s.tk = testkit.NewTestKit(c, s.store)
+	s.tk.MustExec("use test")
+	s.tk.MustExec("drop table if exists abc;")
+	s.tk.MustExec("create table abc(y year, x int, primary key(y));")
+	is := s.dom.InfoSchema()
+	tbl, err := is.TableByName(model.NewCIStr("test"), model.NewCIStr("abc"))
+	c.Assert(err, IsNil)
+	var yearCol *model.ColumnInfo
+	for _, col := range tbl.Meta().Columns {
+		if col.Name.String() == "y" {
+			yearCol = col
+			break
+		}
+	}
+	c.Assert(yearCol, NotNil)
+	c.Assert(yearCol.Tp, Equals, mysql.TypeYear)
+	c.Assert(mysql.HasUnsignedFlag(yearCol.Flag), IsFalse)
+}
+
 func (s *testDBSuite) TestCharacterSetInColumns(c *C) {
 	s.tk = testkit.NewTestKit(c, s.store)
 	s.tk.MustExec("drop database if exists varchar_test;")

executor/show_test.go

@@ -345,6 +345,16 @@ func (s *testSuite) TestShow(c *C) {
 			"  `d` int(11) DEFAULT NULL\n"+
 			") ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin"+"\nPARTITION BY RANGE COLUMNS(a,d,c) (\n  PARTITION p0 VALUES LESS THAN (5,10,\"ggg\"),\n  PARTITION p1 VALUES LESS THAN (10,20,\"mmm\"),\n  PARTITION p2 VALUES LESS THAN (15,30,\"sss\"),\n  PARTITION p3 VALUES LESS THAN (50,MAXVALUE,MAXVALUE)\n)",
 	))
+
+	// Test show create table year type
+	tk.MustExec(`drop table if exists t`)
+	tk.MustExec(`create table t(y year, x int, primary key(y));`)
+	tk.MustQuery(`show create table t`).Check(testutil.RowsWithSep("|",
+		"t CREATE TABLE `t` (\n"+
+			"  `y` year NOT NULL,\n"+
+			"  `x` int(11) DEFAULT NULL,\n"+
+			"  PRIMARY KEY (`y`)\n"+
+			") ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin"))
 }
 
 func (s *testSuite) TestShowVisibility(c *C) {

expression/typeinfer_test.go

@@ -204,7 +204,7 @@ func (s *testInferTypeSuite) createTestCase4Cast() []typeInferTestCase {
 func (s *testInferTypeSuite) createTestCase4Columns() []typeInferTestCase {
 	return []typeInferTestCase{
 		{"c_bit        ", mysql.TypeBit, charset.CharsetBin, mysql.UnsignedFlag, 10, 0},
-		{"c_year       ", mysql.TypeYear, charset.CharsetBin, mysql.UnsignedFlag | mysql.ZerofillFlag, 4, 0},
+		{"c_year       ", mysql.TypeYear, charset.CharsetBin, mysql.ZerofillFlag, 4, 0},
 		{"c_int_d      ", mysql.TypeLong, charset.CharsetBin, 0, 11, 0},
 		{"c_uint_d     ", mysql.TypeLong, charset.CharsetBin, mysql.UnsignedFlag, 10, 0},
 		{"c_bigint_d   ", mysql.TypeLonglong, charset.CharsetBin, 0, 20, 0},

table/column.go

@@ -200,7 +200,7 @@ const defaultPrivileges = "select,insert,update,references"
 // GetTypeDesc gets the description for column type.
 func (c *Column) GetTypeDesc() string {
 	desc := c.FieldType.CompactStr()
-	if mysql.HasUnsignedFlag(c.Flag) && c.Tp != mysql.TypeBit {
+	if mysql.HasUnsignedFlag(c.Flag) && c.Tp != mysql.TypeBit && c.Tp != mysql.TypeYear {
 		desc += " UNSIGNED"
 	}
 	return desc