Question

我有两张包含员工和部门信息的表格。两者看起来如下

员工表：

   ID_emp  ID_dep    year
    3000    4         0
    3001    4         1
    3002    4         2
    3003    16        3
    3004    15        3

部门表：

ID_dep    dep_descr
16       management
4        accounting

现在，我需要找出每个部门雇用超过1年的员工人数，并提供每个部门的员工百分比，相对于雇员超过1年的员工总数。整个公司（所有部门）。

结果应如下所示：

dep_descr   number of employees    percent of total employees
management          12                         5%
accounting          4                         1.6%
...                ...                        ...

Answer 1

这个怎么样？

select 
    concat(cast(count(e.id_emp)/(select count(id_emp) from employee) * 100 as decimal(4,2)), '%') employees_in_dept, d.dep_descr
from employee e
inner join department d
on e.id_dep = d.id_dep
group by d.id_dep

Answer 2

create temp table emp (id_emp int, id_dep int, nyear int);
create temp table dep (id_dep int, desc_dep text);
insert into dep values (16,'management'),(4, 'accounting');
insert into emp values (3000,4,0),(3001,4,1),(3002,4,2),(3003,16,3),(3004,16,3);

with cte (id_dep, desc_dep, num_employees) as
(
select emp.id_dep, dep.desc_dep, count(*)
from emp
    left join dep on emp.id_dep = dep.id_dep
where emp.nyear > 1
group by emp.id_dep, dep.desc_dep
)
select 
    cte.id_dep, 
    cte.desc_dep, 
    cte.num_employees, 
    cte.num_employees * 100 / (select count(*) from emp where emp.nyear > 1)::float as percent_of_total 
from cte;

Answer 3

到目前为止你尝试了什么？您可能需要使用子查询来计算员工总数，并将其用于划分由部门分组的员工数。

MySQL计算值并在一个sql查询中获取百分比

3 个答案: