几个sql多表查询语句，with as

SQL> create table employees

2 (

3 emp_id number(2),

4 name varchar(30),

5 department_id number(4),

6 job_id varchar(30),

7 salary number(8,2),

8 hire_date date);

insert into employees values (1,'zs',10,'xs',2000,to_date('2011-11-11 11:11:11','yyyy-mm-dd hh24:mi:ss'));

insert into employees values (2,'ls',20,'mj',12000,to_date('2010-11-11 11:11:11','yyyy-mm-dd hh24:mi:ss'));

insert into employees values (3,'zs1',10,'xs',5000,to_date('2010-01-11 11:11:11','yyyy-mm-dd hh24:mi:ss'));

insert into employees values (4,'ls1',20,'mj',6000,to_date('2010-12-11 11:11:11','yyyy-mm-dd hh24:mi:ss'));

insert into employees values (5,'zs2',10,'xs',11000,to_date('2001-11-11 11:11:11','yyyy-mm-dd hh24:mi:ss'));

insert into employees values (6,'ls2',20,'mj',18000,to_date('2010-01-11 11:11:11','yyyy-mm-dd hh24:mi:ss'));

insert into employees values (7,'zs3',10,'xs',50000,to_date('2018-11-11 11:11:11','yyyy-mm-dd hh24:mi:ss'));

insert into employees values (8,'ls3',20,'mj',80000,to_date('2018-19-11 11:11:11','yyyy-mm-dd hh24:mi:ss'));

1、查询1到50部门中 哪些年份入职的员工超过1人.

显示年份,人数,其中年份为4位 ,人数按降序排列

SQL> select substr(to_char(hire_date,'yyyy-mm-dd hh24:mi:ss'),1,4),count(*) from employees group by substr(to_char(hire_date,'yyyy-mm-dd hh24:mi:ss'),1,4) having count(*) >1 order by 2 desc;

SUBS COUNT(*)

---- ----------

2010 4

2018 2

2、那些员工的工资高于该部门的平均工资，显示姓名工资，以工资降序排列

SQL> with t1 as (select department_id,avg(salary) salary from employees group by department_id) select employees.name,employees.salary from employees,t1 where employees.department_id=t1.department_id and employees.salary>t1.salary order by employees.salary desc;

NAME SALARY

------------------------------ ----------

ls3 80000

zs3 50000