mysql提示:Illegal mix of collations for operation ‘UNION’

语句很简单 代码如下 ?php $connection=mysql_connect(localhost,root,password); //连接并选择数据库服务器 mysql_select_db(test,$connection); $query=select * from users where; $result=mysql_query($query,$connection); while($row=mysql_fetch_arra

 语句很简单

 代码如下  

$connection=mysql_connect("localhost","root","password"); //连接并选择数据库服务器
mysql_select_db("test",$connection);
$query="select * from users where";
$result=mysql_query($query,$connection);
while($row=mysql_fetch_array($result))
{
echo "用户ID：".$row[0]."
"; //也可以写做$row["user_id"]
echo "用户名：".$row[1]."
"; //也可以写做$row["user_name"]
}
?>

　　运行结果提示

　　Error: Illegal mix of collations (gbk_chinese_ci,IMPLICIT) and (latin1_swedish_ci,COERCIBLE) for operation '='

　　意思是说：操作符“=”比较的字符集不一致，一个是gbk_chinese_ci,一个是latin1_swedish_ci。

　　首先、查看mysql的my.cnf,确认为utf8

 代码如下  

mysql> show variables like "%char%";

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

| Variable_name            | Value                               |

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

| character_set_client     | utf8                                |

| character_set_connection | utf8                                |

| character_set_database   | latin1                              |

| character_set_filesystem | binary                              |

| character_set_results    | utf8                                |

| character_set_server     | utf8                                |

| character_set_system     | utf8                                |

| character_sets_dir       | D:/MySQL Server 5.0/share/charsets/ |

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

8 rows in set (0.00 sec)

 

 

mysql> show variables like "%coll%";

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

| Variable_name        | Value             |

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

| collation_connection | utf8_general_ci   |

| collation_database   | latin1_swedish_ci |

| collation_server     | utf8_general_ci   |

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

3 rows in set (0.00 sec)

　　然后将数据库中所有编码方式改为统一：

 代码如下  

mysql> set character_set_database=utf8;

Query OK, 0 rows affected (0.00 sec)

 

mysql> set collation_database= utf8_general_ci

　　重新查看字符集及数据表字段编码字符是否一致：

　　总结

　　utf8_bin

　　utf8_general_ci

　　utf8_unicode_ci

　　utf8_bin 与 utf8_general_ci 可以

　　utf8_bin 与 utf8_unicode_ci 可以

　　utf8_general_ci 与 utf8_unicode_ci 不可以

，