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首页 > 数据库 > Mysql > MySQL 5.7升级8.0排序规则问题

MySQL 5.7升级8.0后出现排序规则问题的解决方案汇总

作者:爱可生开源社区

MySQL 5.7.34 升级到 8.0.32 后部分查询语句报错如下,ERROR 1267 (HY000),比较操作中使用不同的字符集或排序规则通常会触发此问题,所以本文给大家介绍了MySQL 5.7升级8.0后出现排序规则问题的解决方案汇总,需要的朋友可以参考下

比较操作中使用不同的字符集或排序规则通常会触发此问题,MySQL 8.0 默认 COLLATE 为 utf8mb4_0900_ai_ci 和 对应列 COLLATE 的 utf8mb4_general_ci 不匹配。

问题现象

MySQL 5.7.34 升级到 8.0.32 后部分查询语句报错如下:

ERROR 1267 (HY000): Illegal mix of collations (utf8mb4_general_ci,IMPLICIT) and (utf8mb4_0900_ai_ci,IMPLICIT) for operation 'find_in_set'

问题原因

比较操作中使用不同的字符集或排序规则通常会触发此问题,MySQL 8.0 默认 COLLATE 为 utf8mb4_0900_ai_ci 和 对应列 COLLATE 的 utf8mb4_general_ci 不匹配。

问题重现过程

创建测试表。

CREATE TABLE `t01` (
  `ID` varchar(30) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL,
  `A_CODE` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
  `B_CODE` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
  PRIMARY KEY (`ID`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci ROW_FORMAT=DYNAMIC;

执行查询语句。

SELECT AAA.* FROM(
SELECT 
@xxx AS _xxx,
( SELECT @xxx := GROUP_CONCAT( A_CODE ) FROM t01 WHERE FIND_IN_SET( B_CODE, @xxx ) ) AS cxxx
FROM
t01,( SELECT @xxx := 'xxx') b
WHERE @xxx IS NOT NULL) ID,t01 AAA
WHERE
FIND_IN_SET( AAA.A_CODE, ID._xxx )
order by A_CODE;

报错。

ERROR 1267 (HY000): Illegal mix of collations (utf8mb4_general_ci,IMPLICIT) and (utf8mb4_0900_ai_ci,IMPLICIT) for operation 'find_in_set'

问题分析

查看默认排序规则。

mysql> show collation like 'utf8mb4_0900_ai_ci';
+--------------------+---------+-----+---------+----------+---------+---------------+
| Collation          | Charset | Id  | Default | Compiled | Sortlen | Pad_attribute |
+--------------------+---------+-----+---------+----------+---------+---------------+
| utf8mb4_0900_ai_ci | utf8mb4 | 255 | Yes     | Yes      |       0 | NO PAD        |
+--------------------+---------+-----+---------+----------+---------+---------------+
1 row in set (0.00 sec)

mysql> show collation like 'utf8mb4_general_ci';
+--------------------+---------+----+---------+----------+---------+---------------+
| Collation          | Charset | Id | Default | Compiled | Sortlen | Pad_attribute |
+--------------------+---------+----+---------+----------+---------+---------------+
| utf8mb4_general_ci | utf8mb4 | 45 |         | Yes      |       1 | PAD SPACE     |
+--------------------+---------+----+---------+----------+---------+---------------+
1 row in set (0.00 sec)

mysql> SELECT * FROM INFORMATION_SCHEMA.COLLATIONS WHERE IS_DEFAULT='Yes' and CHARACTER_SET_NAME='utf8mb4';
+--------------------+--------------------+-----+------------+-------------+---------+---------------+
| COLLATION_NAME     | CHARACTER_SET_NAME | ID  | IS_DEFAULT | IS_COMPILED | SORTLEN | PAD_ATTRIBUTE |
+--------------------+--------------------+-----+------------+-------------+---------+---------------+
| utf8mb4_0900_ai_ci | utf8mb4            | 255 | Yes        | Yes         |       0 | NO PAD        |
+--------------------+--------------------+-----+------------+-------------+---------+---------------+
1 row in set (0.00 sec)

查看相关参数。

mysql> show variables like '%collation%';
+-------------------------------+--------------------+
| Variable_name                 | Value              |
+-------------------------------+--------------------+
| collation_connection          | utf8mb4_0900_ai_ci |
| collation_database            | utf8mb4_general_ci |
| collation_server              | utf8mb4_general_ci |
| default_collation_for_utf8mb4 | utf8mb4_0900_ai_ci |
+-------------------------------+--------------------+
4 rows in set (0.00 sec)

其中:
mysql> show global variables like '%collation%';
+-------------------------------+--------------------+
| Variable_name                 | Value              |
+-------------------------------+--------------------+
| collation_connection          | utf8mb4_general_ci |
| collation_database            | utf8mb4_general_ci |
| collation_server              | utf8mb4_general_ci |
| default_collation_for_utf8mb4 | utf8mb4_0900_ai_ci |
+-------------------------------+--------------------+
4 rows in set (0.00 sec)

查看配置文件参数。

mysql@CJC-DB-01:/home/mysql$cat /etc/my.cnf 
......
[mysqld]
collation_server = utf8mb4_general_ci

可以看到,客户端局部会话变量 collation_connection 的值为 utf8mb4_0900_ai_ci,而全局变量值为 utf8mb4_general_ci,两者不一致。

这是由于服务端在客户端连接时,获取了客户端对字符集和排序规则的缺省设置,也就是 utf8mb4_0900_ai_ci

解决方案

1. 修改参数

参数collation_connection 在客户端局部变量值和全局变量值不一致,如何改成一致?官网参考材料

--character-set-client-handshake
Command-Line Format:--character-set-client-handshake[={OFF|ON}]
Deprecated:8.0.35
Type:Boolean
Default Value:ON

参数说明

此选项在 MySQL 8.0.35 及更高版本的 MySQL 8.0 中已被弃用。在该版本中,无论何时使用此选项,都会发出警告,并将在未来版本的 MySQL 中删除。

依赖此选项的应用程序应该尽快开始迁移。

添加 my.cnf 参数。

[mysqld]
skip-character-set-client-handshake

重启 MySQL。

mysqladmin -uroot -p****** shutdown
mysqld --defaults-file=/etc/my.cnf --user=mysql &

登录

mysql -uroot -p cjc

查看参数,collation_connection 参数值修改成功

mysql> show global variables like '%collation%';
+-------------------------------+--------------------+
| Variable_name                 | Value              |
+-------------------------------+--------------------+
| collation_connection          | utf8mb4_general_ci |
| collation_database            | utf8mb4_general_ci |
| collation_server              | utf8mb4_general_ci |
| default_collation_for_utf8mb4 | utf8mb4_0900_ai_ci |
+-------------------------------+--------------------+
4 rows in set (0.00 sec)

mysql> show variables like '%collation%';
+-------------------------------+--------------------+
| Variable_name                 | Value              |
+-------------------------------+--------------------+
| collation_connection          | utf8mb4_general_ci |
| collation_database            | utf8mb4_general_ci |
| collation_server              | utf8mb4_general_ci |
| default_collation_for_utf8mb4 | utf8mb4_0900_ai_ci |
+-------------------------------+--------------------+
4 rows in set (0.01 sec)

再次执行,问题解决。

SELECT AAA.* FROM(
SELECT 
@xxx AS _xxx,
( SELECT @xxx := GROUP_CONCAT( A_CODE ) FROM t01 WHERE FIND_IN_SET( B_CODE, @xxx ) ) AS cxxx
FROM
t01,( SELECT @xxx := 'xxx') b
WHERE @xxx IS NOT NULL) ID,t01 AAA
WHERE
FIND_IN_SET( AAA.A_CODE, ID._xxx )
order by A_CODE;
Empty set, 2 warnings (0.00 sec)

2. 修改表 COLLATE

先改回原参数,查询报错。

SELECT AAA.* FROM(
SELECT 
@xxx AS _xxx,
( SELECT @xxx := GROUP_CONCAT( A_CODE ) FROM t01 WHERE FIND_IN_SET( B_CODE, @xxx ) ) AS cxxx
FROM
t01,( SELECT @xxx := 'xxx') b
WHERE @xxx IS NOT NULL) ID,t01 AAA
WHERE
FIND_IN_SET( AAA.A_CODE, ID._xxx )
order by A_CODE;
ERROR 1267 (HY000): Illegal mix of collations (utf8mb4_general_ci,IMPLICIT) and (utf8mb4_0900_ai_ci,IMPLICIT) for operation 'find_in_set'

修改表排序规则。

mysql> show create table t01\G;
*************************** 1. row ***************************
       Table: t01
Create Table: CREATE TABLE `t01` (
  `ID` varchar(30) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL,
  `A_CODE` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
  `B_CODE` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
  PRIMARY KEY (`ID`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci ROW_FORMAT=DYNAMIC
1 row in set (0.00 sec)

ERROR: 
No query specified

修改所有列 COLLATE,实际上只修改 A_CODEB_CODE 列 COLLATE 也可解决此问题。

ALTER TABLE cjc.t01 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci;
ALTER TABLE cjc.t01 MODIFY COLUMN `ID` varchar(30) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL;
ALTER TABLE cjc.t01 MODIFY COLUMN `A_CODE` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL;
ALTER TABLE cjc.t01 MODIFY COLUMN `B_CODE` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL;

再次执行,问题解决。

SELECT AAA.* FROM(
SELECT 
@xxx AS _xxx,
( SELECT @xxx := GROUP_CONCAT( A_CODE ) FROM t01 WHERE FIND_IN_SET( B_CODE, @xxx ) ) AS cxxx
FROM
t01,( SELECT @xxx := 'xxx') b
WHERE @xxx IS NOT NULL) ID,t01 AAA
WHERE
FIND_IN_SET( AAA.A_CODE, ID._xxx )
order by A_CODE;

Empty set, 2 warnings (0.00 sec)

查看表结构。

mysql> show create table t01\G;
*************************** 1. row ***************************
       Table: t01
Create Table: CREATE TABLE `t01` (
  `ID` varchar(30) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
  `A_CODE` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
  `B_CODE` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
  PRIMARY KEY (`ID`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci ROW_FORMAT=DYNAMIC
1 row in set (0.00 sec)

3. 修改 SQL 语句

将 A_CODEB_CODE 列的 COLLATE 在 SQL 语句中转换为 utf8mb4_0900_ai_ci

改写后的SQL如下:

SELECT AAA.* FROM(
SELECT 
@xxx AS _xxx,
( SELECT @xxx := GROUP_CONCAT( A_CODE COLLATE utf8mb4_0900_ai_ci ) FROM t01 WHERE FIND_IN_SET( B_CODE COLLATE utf8mb4_0900_ai_ci, @xxx ) ) AS cxxx
FROM
t01,( SELECT @xxx := 'xxx') b
WHERE @xxx IS NOT NULL) ID,t01 AAA
WHERE
FIND_IN_SET( AAA.A_CODE COLLATE utf8mb4_0900_ai_ci, ID._xxx )
order by A_CODE;

总结

比较三种解决方案,每种解决方案适用场景不同,请根据实际情况选择解决方案。

以上就是MySQL 5.7升级8.0后出现排序规则问题的解决方案汇总的详细内容,更多关于MySQL 5.7升级8.0排序规则问题的资料请关注脚本之家其它相关文章!

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