用了很久的PHP数据库操作类|简单|方便|易懂

    class Conn_DB{
        var $severname = "用户名"; //
        var $dbname = "数据库名"; //
        var $username ="帐号"; //
        var $password ="密码"; //
        var $link_id; //
        var $num_rows; //
        var $query_id; //
        var $affected_rows; //
        var $insertid; //
        function Conn_DB(){#$servername,$dbname,$username,$password
            $this -> link_id = @mysql_connect($severname,$username,$password) or die ($this-> link_id = "Link Server Error!");
            $this -> link_id = @mysql_select_db($dbname) or die ($this-> link_id = "Link DataBase Error!");
            mysql_query("set names 'gbk'");
            return $this -> link_id;
        }
        function Quit($link_id){   //关闭连接
            mysql_close($this->link_id);
        }
        function free_result($query_id){ //释放资源
            @mysql_free_result($query_id);
        }
        function Query($sql_str){//返回单条数据
            $this->query_id = @mysql_query($sql_str);
            $this->num_rows = @mysql_num_rows($this->query_id);
            $RS=@mysql_fetch_array($this->query_id,MYSQL_ASSOC);
            if ($this->num_rows == 0) {
                $RS = FALSE;
            }
            $this->free_result($this->query_id);
            return $RS;
        }
        function Query_array($sql_str){//返回多条数据 
            $this->query_id=@mysql_query($sql_str);
            $this->num_rows=@mysql_num_rows($this->query_id) ;
            if ($this->num_rows == 0) {
                $RSarray = FALSE;
                $this->free_result($this->query_id);
                return $RSarray;
            }else{
                for($i=0;$i<$this->num_rows;$i++){
                    $RSarray[$i]=mysql_fetch_array($this->query_id,MYSQL_ASSOC);
                }
                $this->free_result($this->query_id);
                return $RSarray;
            }
        }
        function Query_noreturn($sql_str){//没有任何返回值
            $this->query_id = mysql_query($sql_str);
            $this->affected_rows = @mysql_affected_rows();
            if ($this->query_id){
                $RS = TRUE;
                return $RS;
            }else{
                $RS = FALSE;
                return $RS;
            }
        }
    }
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