SQL 2 语句创建一个 3 语句，并将 2 连接在一起答案

【问题标题】：SQL 2 statements creating a 3 statement, and joining the 2 togetherSQL 2 语句创建一个 3 语句，并将 2 连接在一起
【发布时间】：2013-01-29 14:18:24
【问题描述】：

这是我的 SQL 语句：

SELECT repnr, DATEDIFF(day, MIN(start), MAX(start) +1) AS DaysTotal
FROM TBLstatus 
WHERE status IN (1, 2, 3, 4, 8, 11, 20, 7, 23)
GROUP BY repnr HAVING COUNT(*) = 2 AND MAX(Start) > GETDATE()-30

Select repnr as repnr, CONVERT(float, SUM(DATEDIFF(day, start, slut))) as extern
From TBLstatus 
where status IN (5, 15, 17)
group by repnr

第一个会返回这个数据：

repnr daystotal
1000  100
1001  90
1003  91

和第二条语句：

repnr extern
900   100
901   102
1000  21
1003  23

我想要的是 repnr（这是一个 ID）匹配的地方，我想减去 to 值，所以我看起来像这样：

repnr result
1000  79
1003  68

我如何为 MSSQL 执行此操作。

【问题讨论】：

标签： sql-server select join

【解决方案1】：

SELECT q1.repnr, q1.daystotal - q2.extern as [result]
FROM
(
SELECT repnr, DATEDIFF(day, MIN(start), MAX(start) +1) AS DaysTotal
FROM TBLstatus 
WHERE status IN (1, 2, 3, 4, 8, 11, 20, 7, 23)
GROUP BY repnr HAVING COUNT(*) = 2 AND MAX(Start) > GETDATE()-30
)q1
INNER JOIN 
(
Select repnr as repnr, CONVERT(float, SUM(DATEDIFF(day, start, slut))) as extern
From TBLstatus 
where status IN (5, 15, 17)
group by repnr
)q2 ON q1.repnr = q2.repnr

【讨论】：

【解决方案2】：

将您的查询设置为子查询并加入您的密钥，您应该一切顺利。

select repnr, DaysTotal - extern as result from (SELECT repnr, DATEDIFF(day, MIN(start), MAX(start) +1) AS DaysTotal
FROM TBLstatus 
WHERE status IN (1, 2, 3, 4, 8, 11, 20, 7, 23)
GROUP BY repnr HAVING COUNT(*) = 2 AND MAX(Start) > GETDATE()-30) a inner join (Select repnr as repnr, CONVERT(float, SUM(DATEDIFF(day, start, slut))) as extern
From TBLstatus 
where status IN (5, 15, 17)
group by repnr) b on a.repnr = b.repnr

【讨论】：

@Mathias 请问你为什么不接受我的答案，这个答案和我的有什么区别？
这个好像更好，更短，select语句合并在一起了。
@Mathias 查询完全一样！他只是删除了换行符。

【解决方案3】：

SELECT a.repnr, ABS(A.daystotal - b.extern) AS result
FROM(
SELECT repnr, DATEDIFF(day, MIN(start), MAX(start) +1) AS DaysTotal
FROM TBLstatus 
WHERE status IN (1, 2, 3, 4, 8, 11, 20, 7, 23)
GROUP BY repnr HAVING COUNT(*) = 2 AND MAX(Start) > GETDATE()-30
)A
JOIN(
Select repnr as repnr, CONVERT(float, SUM(DATEDIFF(day, start, slut))) as extern
From TBLstatus 
where status IN (5, 15, 17)
group by repnr
)B
ON A.repnr = b.repnr

【讨论】：