有两种不同的字符集：

• MySQL假定字符串由客户端发送的编码（ character_set_client ）;和


• MySQL会传送其回应的编码（ character_set_results ）。

• the encoding in which MySQL assumes strings are sent by the client (character_set_client); and
• the encoding in which MySQL will send its responses (character_set_results).

的这些变量使用PDO，您可以获取相关的 显示变量 语句;例如：

To ascertain the current value of these variables using PDO, you could fetch the results of the relevant SHOW VARIABLES statement; for example:

$qry = $db->query("SHOW VARIABLES LIKE 'character_set_client'");

mysql_client_encoding（） 有点含糊，因为它指出：

The documentation for mysql_client_encoding() is somewhat ambiguous, as it states:

从MySQL中检索 character_set 变量。

但是，没有这样的服务器系统变量存在：所以我不知道它会返回什么。

However, no such server system variable exists: so I'm not sure which it would return.

最后，不是设置 MYSQL_ATTR_INIT_COMMAND ，您可以在DSN中指定所需的字符集（如在手册）：

Finally, rather than setting a MYSQL_ATTR_INIT_COMMAND, you can specify your desired character set in the DSN (as mentioned in the manual):

$db = new PDO("mysql:dbname=$db;host=$host;charset=$charset", $user, $password);