Schema: replace invalid default value to zero value under not strict …

…sql mode (pingcap#8850)

close pingcap#8803

tests/fullstack-test2/variables/set_sql_mode_ansi.test

@@ -0,0 +1,51 @@
+# Copyright 2024 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.
+
+# use an empty string as the default value for decimal column
+mysql> set sql_mode='ansi'; CREATE TABLE test.t (id int, i int default '1.1', f float default 'a', d decimal(10,2) default 'b', y year default 'f');
+
+mysql> set sql_mode='ansi'; insert into test.t (id) values (1),(2),(3),(4);
+mysql> alter table test.t set tiflash replica 1;
+
+func> wait_table test t
+
+mysql> set sql_mode='ansi'; insert into test.t (id) values (5),(6),(7),(8);
+mysql> set sql_mode='ansi'; set session tidb_isolation_read_engines='tikv'; select * from test.t;
++------+------+------+------+------+
+| id   | i    | f    | d    | y    |
++------+------+------+------+------+
+|    1 |    1 |    0 | 0.00 | 0000 |
+|    2 |    1 |    0 | 0.00 | 0000 |
+|    3 |    1 |    0 | 0.00 | 0000 |
+|    4 |    1 |    0 | 0.00 | 0000 |
+|    5 |    1 |    0 | 0.00 | 0000 |
+|    6 |    1 |    0 | 0.00 | 0000 |
+|    7 |    1 |    0 | 0.00 | 0000 |
+|    8 |    1 |    0 | 0.00 | 0000 |
++------+------+------+------+------+
+mysql> set sql_mode='ansi'; set session tidb_isolation_read_engines='tiflash'; select * from test.t;
++------+------+------+------+------+
+| id   | i    | f    | d    | y    |
++------+------+------+------+------+
+|    1 |    1 |    0 | 0.00 | 0000 |
+|    2 |    1 |    0 | 0.00 | 0000 |
+|    3 |    1 |    0 | 0.00 | 0000 |
+|    4 |    1 |    0 | 0.00 | 0000 |
+|    5 |    1 |    0 | 0.00 | 0000 |
+|    6 |    1 |    0 | 0.00 | 0000 |
+|    7 |    1 |    0 | 0.00 | 0000 |
+|    8 |    1 |    0 | 0.00 | 0000 |
++------+------+------+------+------+
+
+mysql> drop table test.t;