mysql - MySql 中的非法混合排序规则错误

Question

刚刚从上一个问题中得到了这个答案，它很有效!

SELECT username, (SUM(rating)/COUNT(*)) as TheAverage, Count(*) as TheCount 
FROM ratings WHERE month='Aug' GROUP BY username HAVING TheCount > 4
ORDER BY TheAverage DESC, TheCount DESC

但是当我把这个额外的位插入它时会出现这个错误:

Documentation #1267 - Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (latin1_general_ci,IMPLICIT) for operation '='

SELECT username, (SUM(rating)/COUNT(*)) as TheAverage, Count(*) as TheCount FROM 
ratings WHERE month='Aug' 
**AND username IN (SELECT username FROM users WHERE gender =1)**
GROUP BY username HAVING TheCount > 4 ORDER BY TheAverage DESC, TheCount DESC

表格是:

id、用户名、等级、月份

Answer 1

以下是检查哪些列是错误排序规则的方法:

SELECT table_schema, table_name, column_name, character_set_name, collation_name

FROM information_schema.columns

WHERE collation_name = 'latin1_general_ci'

ORDER BY table_schema, table_name,ordinal_position; 

这是修复它的查询:

ALTER TABLE tbl_name CONVERT TO CHARACTER SET latin1 COLLATE 'latin1_swedish_ci';

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