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

$connection=mysql_connect("localhost","root","password"); //连接并选择数据库服务器
mysql_select_db("test",$connection);
$query="select * from users where name='你好'";
$result=mysql_query($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"]
}
?>

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)

mysql> set character_set_database=utf8;

Query OK, 0 rows affected (0.00 sec)

mysql> set collation_database= utf8_general_ci