Closed
Description
Bug Report
Please answer these questions before submitting your issue. Thanks!
1. Minimal reproduce step (Required)
mysql> create table t2(id int, v1 char(10) collate utf8mb4_general_ci, v2 char(10) collate utf8mb4_bin);
Query OK, 0 rows affected (0.01 sec)
mysql> insert into t2 values(1,'a','A'),(2,'A','A'),(3,'a ','A'),(4,'A ','A');
Query OK, 4 rows affected (0.00 sec)
Records: 4 Duplicates: 0 Warnings: 0
mysql> select count(distinct v1,v2) from t2;
+-----------------------+
| count(distinct v1,v2) |
+-----------------------+
| 1 |
+-----------------------+
1 row in set (0.01 sec)
mysql>
mysql>
mysql>
mysql>
mysql> select count(distinct v1,v2) from t2;
+-----------------------+
| count(distinct v1,v2) |
+-----------------------+
| 1 |
+-----------------------+
1 row in set (0.00 sec)
mysql> select * from t2;
+------+------+------+
| id | v1 | v2 |
+------+------+------+
| 1 | a | A |
| 2 | A | A |
| 3 | a | A |
| 4 | A | A |
+------+------+------+
4 rows in set (0.00 sec)
2. What did you expect to see? (Required)
mysql> select count(distinct v1,v2) from t2;
+-----------------------+
| count(distinct v1,v2) |
+-----------------------+
| 1 |
+-----------------------+
1 row in set (0.00 sec)
3. What did you see instead (Required)
mysql> select count(distinct v1,v2) from t2;
+-----------------------+
| count(distinct v1,v2) |
+-----------------------+
| 2 |
+-----------------------+
1 row in set (0.00 sec)
4. What is your TiDB version? (Required)
master@a7fdc2a056636119202c16feefb91f25702a8f4f