我需要创建低于结果的查询 我添加了我的表格以便更好地理解。
QTable:
QID Name
-------
1 x
1 y
2 z
FTable:
QID FID
-------
1 1
1 2
2 3
Inner join with :
FID Type
-------
1 1
1 2
1 3
1 4
2 2
2 3
2 3
3 1
3 3
3 3
我需要这样结果:
result:
QID FID-Count Type(1)-count Type(2)-count Type(3)-count Type(4)-count
-----------------------------------------------------------------
1 2 1 2 3 1
2 1 1 0 2 0
感谢您的帮助。
答案 0 :(得分:3)
通常,您可以使用GROUP BY和SUM + CASE模拟一个数据透视:
SELECT
T1.QID,
COUNT(DISTINCT T1.FID) as FIDCOUNT,
SUM(CASE WHEN Type=1 THEN 1 ELSE 0 END) as Type1Cnt,
SUM(CASE WHEN Type=2 THEN 1 ELSE 0 END) as Type2Cnt,
SUM(CASE WHEN Type=3 THEN 1 ELSE 0 END) as Type3Cnt,
SUM(CASE WHEN Type=4 THEN 1 ELSE 0 END) as Type4Cnt
FROM QFTable as T1
JOIN T2 ON
T1.FID=T2.FID
GROUP BY T1.QID
ORDER BY QID