Very interesting... Now, be ready. I looked at all of the "add collate" solutions and to me, those are band aid fixes. The reality is the database design was "bad". Yes, standard changes and new things gets added, blah blah, but it does not change the bad database design fact. I refuse to go with the route of adding "collate" all over the SQL statements just to get my query to work. The only solution that works for me and will virtually eliminate the need to tweak my code in the future is to re-design the database/tables to match the character set that I will live with and embrace for the long term future. In this case, I choose to go with the character set "utf8mb4".

因此，当您遇到“非法”错误消息时，这里的解决方案是重新设计数据库和表。这比听起来要简单快捷得多。甚至可能不需要导出数据并从CSV重新导入数据。更改数据库的字符集，并确保所有表的字符集都匹配。

使用这些命令来指导您:

SHOW VARIABLES LIKE "collation_database";
SHOW TABLE STATUS;

现在，如果您喜欢在这里或那里添加“collate”，并通过强制完全“重写”来增强代码，请听我的猜测。

Very interesting... Now, be ready. I looked at all of the "add collate" solutions and to me, those are band aid fixes. The reality is the database design was "bad". Yes, standard changes and new things gets added, blah blah, but it does not change the bad database design fact. I refuse to go with the route of adding "collate" all over the SQL statements just to get my query to work. The only solution that works for me and will virtually eliminate the need to tweak my code in the future is to re-design the database/tables to match the character set that I will live with and embrace for the long term future. In this case, I choose to go with the character set "utf8mb4".

因此，当您遇到“非法”错误消息时，这里的解决方案是重新设计数据库和表。这比听起来要简单快捷得多。甚至可能不需要导出数据并从CSV重新导入数据。更改数据库的字符集，并确保所有表的字符集都匹配。

使用这些命令来指导您:

SHOW VARIABLES LIKE "collation_database";
SHOW TABLE STATUS;

现在，如果您喜欢在这里或那里添加“collate”，并通过强制完全“重写”来增强代码，请听我的猜测。

有时转换字符集可能是危险的，特别是在具有大量数据的数据库上。我认为最好的选择是使用“二进制”操作符:

e.g : WHERE binary table1.column1 = binary table2.column1

MySQL真的不喜欢混合排序规则，除非它可以将它们强制到同一个排序规则(这在您的情况下显然是不可行的)。难道不能通过COLLATE子句强制使用相同的排序规则吗?(或更简单的二进制快捷方式，如果适用…)

在我的例子中，函数的默认返回类型是来自数据库的类型/排序规则(utf8mb4_general_ci)，但数据库列是ascii。

WHERE ascii_col = md5(concat_ws(',', a,b,c))

权宜之计是

WHERE ascii_col = BINARY md5(concat_ws(',', a,b,c))

我有一个类似的问题，试图使用FIND_IN_SET过程与字符串变量。

SET @my_var = 'string1,string2';
SELECT * from my_table WHERE FIND_IN_SET(column_name,@my_var);

并且正在接收错误

错误码:1267。排序规则的非法混合(utf8_unicode_ci,IMPLICIT) 和(utf8_general_ci，隐式)操作'find_in_set'

简短的回答:

不需要更改任何collation_YYYY变量，只需在变量声明旁边添加正确的排序规则，即。

SET @my_var = 'string1,string2' COLLATE utf8_unicode_ci;
SELECT * from my_table WHERE FIND_IN_SET(column_name,@my_var);

长一点的回答:

我首先检查了排序变量:

mysql> SHOW VARIABLES LIKE 'collation%';
    +----------------------+-----------------+
    | Variable_name        | Value           |
    +----------------------+-----------------+
    | collation_connection | utf8_general_ci |
    +----------------------+-----------------+
    | collation_database   | utf8_general_ci |
    +----------------------+-----------------+
    | collation_server     | utf8_general_ci |
    +----------------------+-----------------+

然后我查看了表格整理:

mysql> SHOW CREATE TABLE my_table;

CREATE TABLE `my_table` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `column_name` varchar(40) COLLATE utf8_unicode_ci DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=125 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

这意味着我的变量被配置为默认排序规则utf8_general_ci，而我的表被配置为utf8_unicode_ci。

通过在变量声明旁边添加COLLATE命令，变量排序规则与为表配置的排序规则相匹配。