SQL语句,子查询数?
我有以下SQL表
部
|name|employees|
雇员
|name|gender|type|dead ||John|male |good|yes |
|Mary|female|bad |no |
|Joe |male |ugly|maybe|
我想写一条返回的声明
| type | n of employees | n of male employees | n of departments |
我有
SELECT e.type, count(e), count(d) FROM Department d
JOIN d.employees e
WHERE e.dead = maybe
GROUP BY e.type
当然,这缺少“男性雇员的数量”。由于不确定,我被困在这里,在哪里指定附加子句e.gender = male。
我忘了提:HQL或标准会很好。
回答:
假设原始查询和架构正确:
SELECT e.type,
count(e),
count(d),
count (case when gender = 'male' then 1 else NULL end) AS NumberOfMaleEmployees
from Department d
JOIN d.employees e
WHERE e.dead = 'maybe'
GROUP BY e.type
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