我有一个表 tblPersonaldata
和 tblStudentsadmitted
tblPersonalData
UID Name Gender
------------------------
E1 xyz M
E2 pqr M
E3 mno M
tblStudentsadmitted
UID Status Stage
----------------------
E1 Y 1
E2 Y 2
E3 Y 1
现在我想要这样的数据:
Gender Stage1 Stage2
M 2 1
但在这种情况下,我没有获得女性性别的数据。我想要女性性别的数据,即使它为空
我试过这个:
select
case
when gender='M' then 'Male'
when gender='F' then 'Female'
end as Gender,
sum(case when Stage=1 then 1 else 0) end as Stage1,
sum(case when Stage=2 then 1 else 0) end as Stage2
from tblPersonaldata A inner join
tblStudentsadmitted B on A.UID=B.UID
where B.Status='Y'
group by Gender
最佳答案
<罢工>罢工>
<罢工>SELECT CASE WHEN a.Gender = 'M' THEN 'Male' ELSE 'FEMALE' END Gender,
SUM(CASE WHEN Stage = 1 THEN 1 ELSE 0 END) Stage1,
SUM(CASE WHEN Stage = 2 THEN 1 ELSE 0 END) Stage2
FROM personal a
LEFT JOIN studentadmitted b
ON a.UID = b.UID AND b.Status = 'Y'
GROUP BY a.Gender
罢工><罢工>罢工>
SELECT CASE WHEN c.Gender = 'M' THEN 'Male' ELSE 'Female' END Gender,
SUM(CASE WHEN Stage = 1 THEN 1 ELSE 0 END) Stage1,
SUM(CASE WHEN Stage = 2 THEN 1 ELSE 0 END) Stage2
FROM (SELECT 'F' Gender UNION SELECT 'M' Gender) c
LEFT JOIN personal a
ON a.Gender = c.Gender
LEFT JOIN studentadmitted b
ON a.UID = b.UID AND b.Status = 'Y'
GROUP BY c.Gender
输出
╔════════╦════════╦════════╗
║ GENDER ║ STAGE1 ║ STAGE2 ║
╠════════╬════════╬════════╣
║ Female ║ 0 ║ 0 ║
║ Male ║ 2 ║ 1 ║
╚════════╩════════╩════════╝
关于sql - 分组依据不显示所有行,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/15360098/