From 5fa3da7e354d0ccb484dcd9f44d080f58e092ff4 Mon Sep 17 00:00:00 2001
From: Benjamin2037 <benjamin2037@sina.com>
Date: Wed, 30 Mar 2022 15:46:29 +0800
Subject: [PATCH] DDL: Wrong Date type colunm's default value (#33571)

ref pingcap/tidb#30358
---
 ddl/column_test.go | 50 ++++++++++++++++++++++++++++++++++++++++++++++
 ddl/ddl_api.go     |  2 +-
 2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/ddl/column_test.go b/ddl/column_test.go
index ae743d36ba..0f142967b9 100644
--- a/ddl/column_test.go
+++ b/ddl/column_test.go
@@ -907,3 +907,53 @@ func testGetTable(t *testing.T, dom *domain.Domain, tableID int64) table.Table {
 	require.True(t, exist)
 	return tbl
 }
+
+func TestGetDefaultValueOfColumn(t *testing.T) {
+	store, _, clean := testkit.CreateMockStoreAndDomain(t)
+	defer clean()
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("create table t1 (da date default '1962-03-03 23:33:34', dt datetime default '1962-03-03'," +
+		" ti time default '2020-10-11 12:23:23', ts timestamp default '2020-10-13 12:23:23')")
+
+	tk.MustQuery("show create table t1").Check(testkit.RowsWithSep("|", ""+
+		"t1 CREATE TABLE `t1` (\n"+
+		"  `da` date DEFAULT '1962-03-03',\n"+
+		"  `dt` datetime DEFAULT '1962-03-03 00:00:00',\n"+
+		"  `ti` time DEFAULT '12:23:23',\n"+
+		"  `ts` timestamp DEFAULT '2020-10-13 12:23:23'\n"+
+		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
+
+	tk.MustExec("insert into t1 values()")
+
+	tk.MustQuery("select * from t1").Check(testkit.RowsWithSep("|", ""+
+		"1962-03-03 1962-03-03 00:00:00 12:23:23 2020-10-13 12:23:23"))
+
+	tk.MustExec("alter table t1 add column da1 date default '2020-03-27 20:20:20 123456'")
+
+	tk.MustQuery("show create table t1").Check(testkit.RowsWithSep("|", ""+
+		"t1 CREATE TABLE `t1` (\n"+
+		"  `da` date DEFAULT '1962-03-03',\n"+
+		"  `dt` datetime DEFAULT '1962-03-03 00:00:00',\n"+
+		"  `ti` time DEFAULT '12:23:23',\n"+
+		"  `ts` timestamp DEFAULT '2020-10-13 12:23:23',\n"+
+		"  `da1` date DEFAULT '2020-03-27'\n"+
+		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
+
+	tk.MustQuery("select * from t1").Check(testkit.RowsWithSep("|", ""+
+		"1962-03-03 1962-03-03 00:00:00 12:23:23 2020-10-13 12:23:23 2020-03-27"))
+
+	tk.MustExec("alter table t1 change ts da2 date default '2020-10-10 20:20:20'")
+
+	tk.MustQuery("show create table t1").Check(testkit.RowsWithSep("|", ""+
+		"t1 CREATE TABLE `t1` (\n"+
+		"  `da` date DEFAULT '1962-03-03',\n"+
+		"  `dt` datetime DEFAULT '1962-03-03 00:00:00',\n"+
+		"  `ti` time DEFAULT '12:23:23',\n"+
+		"  `da2` date DEFAULT '2020-10-10',\n"+
+		"  `da1` date DEFAULT '2020-03-27'\n"+
+		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
+
+	tk.MustQuery("select * from t1").Check(testkit.RowsWithSep("|", ""+
+		"1962-03-03 1962-03-03 00:00:00 12:23:23 2020-10-13 2020-03-27"))
+}
diff --git a/ddl/ddl_api.go b/ddl/ddl_api.go
index 5ffcbac725..40d3e9fdf0 100644
--- a/ddl/ddl_api.go
+++ b/ddl/ddl_api.go
@@ -1123,7 +1123,7 @@ func getDefaultValue(ctx sessionctx.Context, col *table.Column, c *ast.ColumnOpt
 	case mysql.TypeEnum:
 		val, err := getEnumDefaultValue(v, col)
 		return val, false, err
-	case mysql.TypeDuration:
+	case mysql.TypeDuration, mysql.TypeDate:
 		if v, err = v.ConvertTo(ctx.GetSessionVars().StmtCtx, &col.FieldType); err != nil {
 			return "", false, errors.Trace(err)
 		}