SQL查詢到不同條件下的兩排比較

Question

我需要一個查詢，以從下表中檢索值

我需要一個查詢計數的項目，其總和（總天數）總數位置1大於總和（totaldays）在位置2

請幫我

Answer 1

Select Count(T1.ProjectId) from (Select ProjectId ,Sum(TotalDay) as TL1 from Project where Location=1 gROUP BY ProjectId) t1 
inner Join 
(Select ProjectId ,Sum(TotalDay) as Tl2 from Project where Location=2 grOUP BY ProjectId) t2 
on 
t1.ProjectId=T2.ProjectId AND t1.tl1>t2.tl2 

Sql Fiddle Demo

Answer 2

試試這個：

DECLARE @a TABLE (
    projectid INT, 
    totalday INT, 
    location INT 
) 

INSERT @a (projectid, totalday, location) 
VALUES 
    (12,   20,  2), 
    (12,   10,  1), 
    (13,   2,   1) 

;WITH CTE AS (
    SELECT projectid, SUM(totalday) AS totalday, location FROM @a GROUP BY projectid, location 
) 
SELECT COUNT(*) 
FROM CTE AS a1 
INNER JOIN CTE AS a2 
    ON a1.projectid = a2.projectid 
WHERE 
    a1.location = 1 AND a2.location = 2 
    AND a1.totalday > a2.totalday 

Answer 3

假設您的數據沒有唯一的密鑰約束，我首先用CTE總結每個項目每個位置的總天數 - 如果您的數據是唯一的，那麼您可以跳過此步驟。

WITH ProjectDays AS 
(
    SELECT projectid, location, SUM(totalday) AS TotalDays 
    FROM Project p 
    GROUP BY projectid, location 
) 
SELECT p1.projectId as ProjectWithMoreTotalDaysInLoc1 
FROM ProjectDays p1 
    INNER JOIN ProjectDays p2 
    ON p1.projectId = p2.projectId 
WHERE 
    p1.location = 1 and p2.location = 2 
    and p1.TotalDays > p2.TotalDays; 

爲了簡單地得到項目（而不是項目本身的列表）的計數，只要切換最終SELECT p1.projectId到SELECT COUNT(*)

Fiddle Here