php - 提取“latin1_swedish_ci”数据库行的问题

Question

我有一个Php脚本应该latin1_swedish_ci从Mysql数据库中提取编码数据，然后使用json_encode方法对提取的数据进行编码，除非提取的行包含特殊字符，否则一切正常é è .....，在这种情况下我没有得到任何结果，并且 HTML 状态代码是200

那是我的功能

public function categorie()
    {   
        // Cross validation if the request method is GET else it will return "Not Acceptable" status
        if($this->get_request_method() != "GET"){
            $this->response('',406);
        }
        $sql = mysql_query("SELECT * FROM categorie", $this->db);
        if(mysql_num_rows($sql) > 0)
        {
            $result = array();
            while($rlt = mysql_fetch_array($sql,MYSQL_ASSOC)){
                $result[] = $rlt;
            }
            // If success everythig is good send header as "OK" and return list of users in JSON format
            $this->response($this->json($result), 200);
        }
        $this->response('',204);    // If no records "No Content" status
    }

    private function json($data){
        if(is_array($data)){
            return json_encode($data);
        }
    }