php mysql 写入乱码

读取正常，写入乱码，则需要加上下面的两行才行。

mysql_query("set character set 'utf8'");//读库  
mysql_query("set names 'utf8'");//写库

-- 查看
MySQL [zencart]> show variables like '%char%';
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | gbk                        |
| character_set_connection | gbk                        |
| character_set_database   | utf8                       |
| character_set_filesystem | binary                     |
| character_set_results    | gbk                        |
| character_set_server     | utf8                       |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.04 sec)

-- seesoin 级别
set character_set_database=gbk;
set character_set_server=gbk;

-- 进程级别（重启msyql服务后会失效）
set global character_set_database=gbk;
set global character_set_server=gbk;


-- 永久级别（重启mysql服务后依然有效）
[mysqld]
character-set-server=utf8 

[client]
default-character-set=utf8 

[mysql]
default-character-set=utf8