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
http://www.nowcoder.com/practice/6a62b6c0a7324350a6d9959fa7c21db3
select dept_no, dept_name,
count(salary)
FROM dept_emp
join salaries using(emp_no)
join departments using(dept_no)
group by dept_no
order by dept_no
窗口函数
select distinct dept_no, dept_name,
count(salary) over(partition by dept_no order by dept_no)
FROM dept_emp
join salaries using(emp_no)
join departments using(dept_no)
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