13-李孝严

select name from gg;

select * from gg where name="d3";

查名字

select * from gg where salary>5000;

薪水大于5000

select dept_id,count(dept_id) from gg group by dept_id;

每个部门人数select

select avg(salary) from gg group by dept_id;

每个部门平均薪资

select * from gg where description is null;

描述字段为空的人

select max(salary) from gg where gender="F" group by dept_id;

每个部门女员工薪资最高的

select * from gg where name like 'l%';

名字是以l开头的用户