Add integration test

Signed-off-by: JaySon-Huang <tshent@qq.com>

Author: JaySon-Huang

tests/fullstack-test2/ddl/issue_10663.test

@@ -0,0 +1,59 @@
+# Copyright 2026 PingCAP, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+mysql> DROP DATABASE IF EXISTS test_100;
+mysql> CREATE DATABASE test_100;
+mysql> CREATE TABLE test_100.t1 (a INT, b INT);
+# prepare some rows inserted before column with default value added
+mysql> INSERT INTO test_100.t1 VALUES (1, 2), (2, 3);
+mysql> ALTER TABLE test_100.t1 set tiflash replica 1;
+func> wait_table test_100 t1
+# add new column with default value and insert some rows
+mysql> ALTER TABLE test_100.t1 ADD COLUMN site_code VARCHAR(64) NOT NULL DEFAULT '100';
+mysql> INSERT INTO test_100.t1 VALUES (12, 13, '100');
+# change the default value so that it may share the same structure with another table
+mysql> ALTER TABLE test_100.t1 MODIFY COLUMN site_code VARCHAR(64) NOT NULL DEFAULT '';
+mysql> ALTER TABLE test_100.t1 ADD PRIMARY KEY (a, site_code);
+
+mysql> DROP DATABASE IF EXISTS test_200;
+mysql> CREATE DATABASE test_200;
+mysql> CREATE TABLE test_200.t1 (a INT, b INT);
+# prepare some rows inserted before column with default value added
+mysql> INSERT INTO test_200.t1 VALUES (1, 2), (2, 3);
+mysql> ALTER TABLE test_200.t1 set tiflash replica 1;
+func> wait_table test_200 t1
+# add new column with default value and insert some rows
+mysql> ALTER TABLE test_200.t1 ADD COLUMN site_code VARCHAR(64) NOT NULL DEFAULT '200';
+mysql> INSERT INTO test_200.t1 VALUES (12, 13, '200');
+# change the default value so that it may share the same structure with test_100.t1
+mysql> ALTER TABLE test_200.t1 MODIFY COLUMN site_code VARCHAR(64) NOT NULL DEFAULT '';
+mysql> ALTER TABLE test_200.t1 ADD PRIMARY KEY (a, site_code);
+
+mysql> set session tidb_isolation_read_engines='tiflash'; select * from test_100.t1 order by a;
++----+----+-----------+
+| a  | b  | site_code |
++----+----+-----------+
+| 1  | 2  | 100       |
+| 2  | 3  | 100       |
+| 12 | 13 | 100       |
++----+----+-----------+
+
+mysql> set session tidb_isolation_read_engines='tiflash'; select * from test_200.t1 order by a;
++----+----+-----------+
+| a  | b  | site_code |
++----+----+-----------+
+| 1  | 2  | 200       |
+| 2  | 3  | 200       |
+| 12 | 13 | 200       |
++----+----+-----------+