写了一个查询所有上级的sql

1.   SELECT
2.   T0.*,T1.lower_count,T1.aicp,T1.user_level
3.   FROM
4.   (
5.   SELECT
6.   @r AS _id,
7.   (
8.   SELECT
9.   @r := invite_user
10.   FROM
11.   fa_user
12.   WHERE
13.   id = _id
14.   ) AS invite_user1,
15.   @l := @l + 1 AS lvl
16.   FROM
17.   (SELECT @r := '用户id', @l := 0) vars,
18.   fa_user h
19.   WHERE
20.   @r <> ''
21.   ) T0
22.   JOIN fa_user T1 ON T0._id = T1.id

报错SQLSTATE[HY000]: General error: 1267 Illegal mix of collations (utf8mb4_0900_ai_ci,IMPLICIT) and (utf8mb4_general_ci,IMPLICIT) for operation '='，。MySQL 8.0.20

我看了下数据库的字符集排序规则 

表的字符集排序规则 

表字段的字符集排序规则 

解决方法：在my.cnf中也做相同编码的配置

1.   [client]
2.   default-character-set = utf8mb4
3.    
4.   [mysqld]
5.   character-set-client-handshake = FALSE
6.   character_set_server = utf8mb4
7.   collation-server = utf8mb4_0900_ai_ci
8.    

如下图 

进入mysql执行 show variables where Variable_name like 'collation%';查看