如何找到表6行中總行數的前三位總和

Question

如何查找表中六行總行數的前三位工資總和。

id  Salary 
01  100 
02  200 
03  300 
04  400 
05  500 
06  600 

Answer 1

你的意思是這樣的：

SELECT SUM(Salary) 
FROM (
    SELECT Salary FROM your_table ORDER BY id LIMIT 3 
) A 

Answer 2

假設它是SQL服務器：

SELECT SUM(Salary) As SalaryTotal 
( 
    SELECT TOP 3 * FROM your_table ORDER BY ID 
) 

如果你想SUM最高3倍的工資，那麼你可以ORDER BY月薪：

SELECT SUM(Salary) As SalaryTotal 
( 
    SELECT TOP 3 * FROM your_table ORDER BY salary DESC  
) 

Answer 3

試試用這個.....

SELECT SUM(salary) 
FROM 
    (SELECT 
     ROW_NUMBER() OVER (ORDER BY id ASC) AS ROW_NUMBER, salary 
    FROM tablename) AS foo 
WHERE 
    ROW_NUMBER <= 3