西安1班-谢康 多表查询作业

1.列出每个部门的平均收入及部门名称;
select avg(incoming),dept_name from emp,dept where dept.dept1=emp.dept2 group by dept_name;
2.财务部门的收入总和；
select sum(emp.incoming) from dept left join emp on dept.dept1=emp.dept2 where dept.dept_name="财务";
3.It技术部入职员工的员工号
select sid from dept left join emp on dept.dept1=emp.dept2 where dept.dept_name="IT技术";
4.财务部门收入超过2000元的员工姓名
select name from dept left join emp on dept.dept1=emp.dept2 where dept.dept_name="财务" and incoming>2000;
5.找出销售部收入最低的员工的入职时间;
select worktime_start from emp where dept2=(select dept1 from dept where dept_name="销售") and incoming=(select min(incoming) from emp where dept2=(select dept1 from dept where dept_name="销售"));
6.找出年龄小于平均年龄的员工的姓名，员工号和部门名称
select emp.name,emp.sid,dept.dept_name from dept left join emp on dept.dept1=emp.dept2 where emp.age<(select avg(age) from emp);
7.列出每个部门收入总和高于9000的部门名称
select dept.dept_name from dept right join (select dept2,sum(incoming) from emp group by dept2 having sum(incoming)>9000)t on dept.dept1=t.dept2;
8.查出财务部门工资少于3800元的员工姓名
select name from emp left join dept on dept.dept1=emp.dept2 where dept.dept_name="财务" and incoming<3800;
9.求财务部门最低工资的员工姓名；
select name from emp left join dept on dept.dept1=emp.dept2 where dept.dept_name="财务" and incoming=(select min(incoming) from emp);
10.找出销售部门中年纪最大的员工的姓名
select name from emp left join dept on dept.dept1=emp.dept2 where dept.dept_name="销售" and age=(select max(age) from emp);
11.求收入最低的员工姓名及所属部门名称
select name,dept_name from emp left join dept on dept.dept1=emp.dept2 where incoming=(select min(incoming) from emp);
12.求员工收入小于4000元的员工部门编号及其部门名称
select dept2,dept_name from emp left join dept on dept.dept1=emp.dept2 where incoming<4000;
13.列出每个部门中收入最高的员工姓名，部门名称，收入，并按照收入降序；
-- select name,dept_name,incoming from emp left join dept on dept.dept1=emp.dept2 group by dept.dept_name having incoming=(select max(incoming) from emp) order by incoming desc;
14.查询财务部低于平均收入的员工号与员工姓名：
select sid, name from emp left join dept on dept.dept1=emp.dept2 where incoming<(select avg(incoming) from emp) and dept.dept_name="财务";
15.列出部门员工数大于1个的部门名称；
-- select dept_name from emp left join dept on dept.dept1=emp.dept2;
-- select count(*),dept2 from emp group by emp.dept2 having count(*)>1;
select dept_name from dept,(select count(*),dept2 from emp group by dept2 having count(*)>1)t where dept.dept1=t.dept2;
16.列出部门员工收入不超过7500，且大于3000的员工年纪及部门名称；
select age,dept_name from emp left join dept on dept.dept1=emp.dept2 where emp.incoming>3000 and emp.incoming<=7500;
17.求入职于20世纪70年代的员工所属部门名称；
select dept.dept_name from dept,emp where dept.dept1=emp.dept2 and emp.worktime_start like "197%";
18.查找张三所在的部门名称；
select dept_name from dept left join emp on dept.dept1=emp.dept2 where emp.name="张三";
19.列出每一个部门中年纪最大的员工姓名，部门名称；
select name,dept_name from dept left join emp on dept.dept1=emp.dept2 group by dept.dept_name having max(emp.age);
20.列出每一个部门的员工总收入及部门名称；
select sum(incoming),dept_name from dept left join emp on dept.dept1=emp.dept2 group by dept.dept_name;
21.列出部门员工收入大于7000的员工号，部门名称；
select sid,dept_name from dept left join emp on dept.dept1=emp.dept2 where emp.incoming>7000;
22.找出哪个部门还没有员工入职；
select dept_name from dept left join emp on dept.dept1=emp.dept2 where name is null;
23.先按部门号大小排序，再依据入职时间由早到晚排序员工信息表 ；
select * from dept left join emp on dept.dept1=emp.dept2 order by dept.dept1 desc,emp.worktime_start asc;
24.求出财务部门工资最高员工的姓名和员工号
select name,sid from dept left join emp on dept.dept1=emp.dept2 where dept.dept_name="财务" having max(incoming);
25.求出工资在7500到8500之间，年龄最大的员工的姓名和部门名称
select emp.`name`,dept.dept_name from dept,emp where dept.dept1=emp.dept2 and emp.age=(select max(age) from emp where incoming between 7500 and 8500);
26.查出大于自己部门平均工资的员工编号及部门名称
select k.es,dept.dept_name from dept,(select emp.sid es,emp.dept2 ed from (select dept2,avg(incoming)a from emp group by dept2)t,emp where t.dept2=emp.dept2 and emp.incoming>t.a)k where dept.dept1=k.ed