miss record when where condition use right %

[zwathz]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

-- table info
CREATE TABLE cp_info (
id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
name varchar(32) COLLATE utf8_general_ci DEFAULT NULL,
PRIMARY KEY (id) /*T![clustered_index] CLUSTERED */,
KEY idx_name (name)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_general_ci AUTO_INCREMENT=1374818

MySQL [cp_center]> explain select * from cp_center.cp_info where name like '秦文政%';
+-------------+---------+------+---------------+---------------+
| id | estRows | task | access object | operator info |
+-------------+---------+------+---------------+---------------+
| TableDual_5 | 0.00 | root | | rows:0 |
+-------------+---------+------+---------------+---------------+
1 row in set (0.00 sec)

-- after drop name index
MySQL [cp_center]> select id, name from cp_center.cp_info where name like '秦文政%'\G
*************************** 1. row ***************************
id: 1310871
name: 秦文政

2. What did you expect to see? (Required)

MySQL [cp_center]> select id, name from cp_center.cp_info where name = '秦文政'\G
*************************** 1. row ***************************
id: 1310871
name: 秦文政

3. What did you see instead (Required)

MySQL [cp_center]> select id, name from cp_center.cp_info where name like '秦文政%'\G
Empty set (0.00 sec)

4. What is your TiDB version? (Required)

Release Version: v5.4.1
Edition: Community
Git Commit Hash: be48447
Git Branch: heads/refs/tags/v5.4.1
UTC Build Time: 2022-05-07 04:31:32
GoVersion: go1.16.4
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false

[zwathz]

*_general_ci collate cause the problem

[aioas]

We have the same problem. Is there any plan to fix it?

[wjhuang2016]

The same as #31174 , fixed by #31278, version: 6.0.0