T-SQL递归

Question

我有一组数据，看起来像下面

Name Time Perc Group Mode Control Cancelled 
A  10:52 10.10 10  0  1   0 
B  09:00 10.23 10  1  1   1 
C  12:02 12.01 12  0  1   1 
D  10:45 12.12 12  1  7   1 
E  12:54 12.56 12  1  3   0 
F  01:01 13.90 13  0  11  1 
G  02:45 13.23 13  1  12  1 
H  09:10 13.21 13  1  1   0 

我需要象下面的输出;

Group Perc Cancelled 
10 20.33  1 
12 36.69  2 
13 40.34  2 

我得到的是类似的东西;

Group Perc Cancelled 
10 20.33  5 
12 36.69  5 
13 40.34  5 

我不知道什么叫这个，我在我的脑海东西，这样称呼它CTE？，但我真的无法弄清楚。

这是我的资料来源;

SELECT Group, SUM(Perc), Cancelled FROM 
(SELECT Group, Perc, (SELECT COUNT(*) FROM tblName WHERE Cancelled=1) AS Cancelled FROM tblName WHERE 1=1 AND Group>=10)dt 
GROUP BY Group, Cancelled 

Answer 1

从你的榜样，你不需要嵌套查询，任何递归，等等...

SELECT 
    Group, 
    SUM(Perc)  AS total_perc, 
    SUM(cancelled) AS total_cancelled 
FROM 
    tblName 
WHERE 
    1=1 
    AND Group >= 10 
GROUP BY 
    Group 

如果你确实有一些不同的数据，那么你可能想使用类似...

SUM(CASE WHEN cancelled > 0 THEN 1 ELSE 0 END) AS total_cancelled