使用與運算聚合函數

Question

我有兩列

在這裏，我需要找到根據下列功能的SQL表，

Z = accelx-AVG(accelx) for every rows. 

Answer 1

子查詢簡單地計算AVG ：

SELECT AccelX - (SELECT AVG(AccelX) FROM T) 
FROM T 

Answer 2

試試這個：

select t1.accelx - t2.avgx as Z 
from TableName as t1 
inner join (
    select avg(accelx) as avgx 
    from TableName 
    ) as t2 
on 1 = 1 

Answer 3

SELECT t1.accelx - t2.avgx as Z, userName 
FROM TableName as t1 
JOIN (SELECT userName, avg(accelx) as avgx 
     FROM TableName 
     GROUP BY userName) as t2  
    ON t1.userName = t2.userName 

Answer 4

這通常使用的AVG解析版本完成：MSSQL Server上

select accelx - avg(accelx) over() 
from mytable; 

Answer 5

TSQL已窗口功能。 OVER Clause

SELECT 
    [AccelX] 
    ,[AccelX] - AVG([AccelX]) OVER() 
FROM T