Mysql设置字符编码可以解决一些常见的问题，比如使用不同的字符集出错的问题，下面就是Mysql设置字符编码解决该问题的具体介绍。
错误是在你的结果集中有两种字符集。
比如说你在两个表联合查询，一个表的字符集是latin1，另一个是utf8，
这样在你的结果集中有两种字符集，mysql会报错误。
一个表中不同的字段使用不同的字符集，也是一个道理。
用SHOW CREATE TABLE table_name;可以看出具体的字符集设置。
查了帮助手册，说是user的字符集没有设,默认为utf8,将其转为latin1或gb2312等字符集
解决方法：
将不同的字符集，转化成统一的字符集。 下面就是Mysql设置字符编码的方法。
After an upgrade to MySQL 4.1, the statement fails: mysql> SELECT SUBSTRING_INDEX(USER(),'@',1); ERROR 1267 (HY000): Illegal mix of collations (utf8_general_ci,IMPLICIT) and (latin1_swedish_ci,COERCIBLE) for operation 'substr_index' The reason this occurs is that usernames are stored using UTF8 (see section 11.6 UTF8 for Metadata). As a result, the USER() function and the literal string '@' have different character sets (and thus different collations): mysql> SELECT COLLATION(USER()), COLLATION('@'); +-------------------+-------------------+ | COLLATION(USER()) | COLLATION('@') | +-------------------+-------------------+ | utf8_general_ci | latin1_swedish_ci | +-------------------+-------------------+ One way to deal with this is to tell MySQL to interpret the literal string as utf8: mysql> SELECT SUBSTRING_INDEX(USER(),_utf8'@',1); +------------------------------------+ | SUBSTRING_INDEX(USER(),_utf8'@',1) | +------------------------------------+ | root | +------------------------------------+ Another way is to change the connection character set and collation to utf8. You can do that with SET NAMES 'utf8' or by setting the character_set_connection and collation_connection system variables directly.
表的编码转换可以用：（MySQL Version > 4.12）
ALTER TABLE tbl_name CONVERT TO CHARACTER SET charset_name;
之前的版本可以用：
ALTER TABLE tbl_name CHARACTER SET charset_name;