1、 最简单的修改方法，就是修改mysql的my.ini文件中的字符集键值， 

如 default-character-set = utf8 

character_set_server = utf8 

修改完后，重启mysql的服务，service mysql restart 

使用 mysql> SHOW VARIABLES LIKE 'character%';查看，发现数据库编码均已改成utf8 

+--------------------------+---------------------------------+ 

| Variable_name | Value | 

+--------------------------+---------------------------------+ 

| character_set_client | utf8 | 

| character_set_connection | utf8 | 

| character_set_database | utf8 | 

| character_set_filesystem | binary | 

| character_set_results | utf8 | 

| character_set_server | utf8 | 

| character_set_system | utf8 | 

| character_sets_dir | D:"mysql-5.0.37"share"charsets" | 

+--------------------------+---------------------------------+ 

2、还有一种修改字符集的方法，就是使用mysql的命令 

mysql> SET character_set_client = utf8 ; 

mysql> SET character_set_connection = utf8 ; 

mysql> SET character_set_database = utf8 ; 

mysql> SET character_set_results = utf8 ; 

mysql> SET character_set_server = utf8 ; 

mysql> SET collation_connection = utf8 ; 

mysql> SET collation_database = utf8 ; 

mysql> SET collation_server = utf8 ; 

3、一般就算设置了表的默认字符集为utf8并且通过UTF-8编码发送查询，你会发现存入数据库的仍然是乱码。问题就出在这个connection连接层上。解决方法是在发送查询前执行一下下面这句： 

SET NAMES 'utf8'; 

它相当于下面的三句指令： 

SET character_set_client = utf8; 

SET character_set_results = utf8; 

SET character_set_connection = utf8;