SQL语句、子查询计数？

Question

我有以下 SQL 表

Department

|name|employees|

Employee

|name|gender|type|dead |
|John|male  |good|yes  |
|Mary|female|bad |no   |
|Joe |male  |ugly|maybe|

我想编写一个返回

| type | n of employees | n of male employees | n of departments |

I've got

SELECT e.type, count(e), count(d) 
FROM Department d 
JOIN d.employees e
WHERE e.dead = maybe 
GROUP BY e.type

That 的语句，当然，缺少“n ofmaleEmployees”。我被困在这里，因为我不确定在哪里指定附加子句 e.gender =male。

我忘了提：HQL 或标准会很好。

Answer 1

假设您的原始查询和架构是正确的：

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

Answer 2

仅供参考：

SELECT 
   e.type, 
   count(e), 
   count(d), 
   sum(case when gender = 'male' then 1 else 0 end)
from Department d 
JOIN d.employees e
WHERE e.dead = 'maybe' 
GROUP BY e.type

适用于 HQL。谢谢大家！