PLSQL 的简单命令之五

--1.  查询和Zlotkey相同部门的员工姓名和雇用日期
select a.last_name,a.hire_date ,b.department_name 
from employees a,departments b
where b.department_name in 
(select department_name 
from departments, employees
where  last_name = 'Zlotkey')

--2.  查询工资比公司平均工资高的员工的员工号，姓名和工资。
select job_id,last_name,salary 
from employees 
where salary >  all (select avg(salary) from employees)

--3.  查询各部门中工资比本部门平均工资高的员工的员工号, 姓名和工资
select a.job_id,a.last_name,a.department_id,a.salary,b.avgsalary
from employees a,(select avg(salary) as avgsalary,department_id from employees 
group by department_id) b
where a.salary > b.avgsalary and a.department_id = b.department_id
/*
其中各部门的平均工资如下
select avg(salary),department_id from employees 
group by department_id

 别名为b的表（查询结果的表 ）
(select avg(salary) as avgsalary,department_id from employees 
group by department_id) b
*/

--4.  查询和姓名中包含字母u的员工在相同部门的员工的员工号和姓名
select job_id,last_name,department_id
from employees
where department_id in (select department_id 
from employees 
where last_name like '%u%')

--5. 查询在部门的location_id为1700的部门工作的员工的员工号
select job_id
from employees
where department_id 
in (select department_id 
from departments 
where location_id =1700) 

--6.查询管理者是King的员工姓名和工资
select manager_id,last_name,salary from employees
where manager_id 
in (select employee_id 
from employees 
where last_name='King'
group by employee_id)


--1.  运行以下脚本创建表my_employees
create table my_employees 
             (id number,
              first_name varchar2(10),
              last_name varchar2(10),
              userid varchar2(10),
              salary number
              );
--2.  显示表my_employees的结构
select * from my_employees

/*3.  向表中插入下列数据
ID  FIRST_NAME  LAST_NAME   USERID   SALARY
1     patel       Ralph    Rpatel   895
2     Dancs      Betty     Bdancs    860
3   Biri       Ben      Bbiri     1100
4   Newman      Chad     Cnewman  750
5  Ropeburn   Audrey    Aropebur 1550
*/  
insert into my_employees values (1,'patel','Ralph','Rpatel',895);
insert into my_employees values (2,'Dancs','Betty','Bdancs',860);
insert into my_employees values (3,'Biri','Ben','Bbiri',1100);
insert into my_employees values (4,'Newman','Chad','Cnewman',750);
insert into my_employees values (5,'Ropeburn','Audrey','Aropebur',1550);

--4.  提交
commit

--5.  将3号员工的last_name修改为“drelxer”
update my_employees set last_name='drelxer' 
where id = 3

--6.  将所有工资少于900的员工的工资修改为1000
update my_employees set salary=1000 where salary < 900

--7.  检查所作的修正
select * from my_employees

--8.  提交
commit

--9.  删除所有数据
delete from my_employees

--10.  检查所作的修正
select * from my_employees

--11.  回滚
rollback

--12.  清空表my_employees
truncate table my_employees