bug: SELECT...WHERE column_2 like '%_a\\\%', returns incorrect result set

[davidshiz]

Have you read the Contributing Guidelines on issues?

• I have read the Contributing Guidelines on issues.

Please confirm if bug report does NOT exists already ?

• I confirm there is no existing issue for this

Describe the problem

mysql> select * from st2 where column_2 like '%_a\\\%';
+------+----------+----------+
| id   | column_2 | column_3 |
+------+----------+----------+
|    1 | _a\\     | 111111   |
+------+----------+----------+
1 row in set (0.00 sec)

Expected behavior

mysql> select * from st2 where column_2 like '%_a\\\%';
+------+----------+----------+
| id   | column_2 | column_3 |
+------+----------+----------+
|    1 | _a\\     | 111111   |
|    4 | _a\      | _12%     |
+------+----------+----------+
2 rows in set (0.00 sec)

How To Reproduce

create table st2(id int ,column_2 varchar(10),column_3 varchar(10));
insert into st2 values(1,'_a\\\\','111111');
insert into st2 values(2,'12%','%12%');
insert into st2 values(3,'a_a','a%');
insert into st2 values(4,'_a\\','_12%');
insert into st2 values(5,'\\a','\\\\_a%12%');

select * from st2 where column_2 like '%_a\\\%';

Environment

root@ub01:~# /stonedb57/install/bin/mysqld --version
/stonedb57/install/bin/mysqld  Ver 5.7.36-StoneDB for Linux on x86_64 (build-)
build information as follow:
        Repository address: https://github.com/stoneatom/stonedb.git:stonedb-5.7-dev
        Branch name: stonedb-5.7-dev
        Last commit ID: 863cebc58
        Last commit time: Date:   Wed Dec 7 14:16:34 2022 +0800
        Build time: Date: Mon Dec 19 14:29:02 CST 2022
root@ub01:~# cat /etc/issue
Ubuntu 20.04.5 LTS \n \l

Are you interested in submitting a PR to solve the problem?

• Yes, I will!

[davidshiz]

similar problem

tianmu:

mysql> select * from st2 where column_2 like '%?_a?\%' escape '?';
Empty set (0.00 sec)

innodb:

mysql> select * from st2 where column_2 like '%?_a?\%' escape '?';
+------+----------+----------+
| id   | column_2 | column_3 |
+------+----------+----------+
|    1 | _a\\     | 111111   |
|    4 | _a\      | _12%     |
+------+----------+----------+
2 rows in set (0.00 sec)

[konghaiya]

ACK