mysql - MySQL SUM的总数COUNT

Seat Type   Quantity left


Business        23
Economy         27
First           15

            Total quantity left : ?

DBMS = MySQL

我已经尝试了以下SQL来打印以上信息

$sql = "SELECT SeatType, COUNT(SeatType)AS quantity
              FROM  seat

              WHERE SeatAvailable = 'Yes'
              GROUP BY SeatType
              ";

我如何总结剩余的总量（例如：23 + 27 + 25）？
谢谢高级的帮助...

最佳答案

SELECT  COALESCE(SeatType, 'Total quantity left') `Seat Type`,
        COUNT(SeatType)AS quantity
FROM    seat
WHERE   SeatAvailable = 'Yes'
GROUP   BY SeatType WITH ROLLUP

SQLFiddle Demo
GROUP BY Modifier