php-GridView显示PHP从数据库中查询获取的信息，英文显示正常，中文显示"??“

public function query($query)
{
$result = mysql_query($query, $this->link)or die("失败");

    $this->result = $result;    if ($result == false)        trigger_error('Uncovered an error in your SQL query script: "' . $this->error() . '"');    return $this->result;}