题解 | #统计各个部门的工资记录数#
统计各个部门的工资记录数
https://www.nowcoder.com/practice/6a62b6c0a7324350a6d9959fa7c21db3
select
d.*,
a.sum
from
departments d
inner join (
select
de.dept_no dept_no,
count(*) sum
from
dept_emp de
inner join salaries s on de.emp_no = s.emp_no
group by
de.dept_no
) a on d.dept_no = a.dept_no
