sql select中两列之间的最高评级

Question

说我有下表:

--------------------
|ID|Yes|No|Filename|
|01|15 |10|1.php   |
|02|12 |5 |2.php   |
|03|6  |1 |3.php   |
--------------------

我想要做的是在sql select语句中应用Yes/Yes + No并回显最高值的文件名.

"是"和"否"会不时更新,因此创建另一列来处理等式会更好吗,还是可以在sql语句中使用等式？选择的陈述对此会是什么样的？

谢谢

Answer 1

对于MySQL,

SELECT  Filename, 
        CAST((Yes / (Yes + No)) AS DECIMAL(10,5)) rating
FROM    table1
WHERE   CAST((Yes / (Yes + No)) AS DECIMAL(10,5)) =
        (
            SELECT MAX(rating)
            FROM
            (
                SELECT CAST((Yes / (Yes + No)) AS DECIMAL(10,5)) rating
                FROM table1
            ) x
        )

SQLFiddle演示

对于 SQL Server

SELECT   TOP 1 WITH TIES Filename, 
         (Yes / (Yes + No)) rating
FROM     table1
ORDER BY rating DESC

SQLFiddle演示