ILLEGAL MIX OF COLLATIONS (UTF8MB4_0900_AI_CI,IMPLICIT) AND (UTF8MB4_GENERAL_CI,IMPLICIT) 错误解决

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