查询出各个部门中工资高于本部门的平均工资的员工数和部门号，并按部门号排序（用sql语句来表达）
1.创建的表格
2.思路：
（1）首先查询各个部门的平均工资
1 select deptid ,avg(salary) as avg_salary from Employee group by deptid;
-----> 查询结果：
（2）利用联合查询的思想进行查询：select * from table1,table2 where table1.name=table2.name
即把Employee表与上表查询出的结果进行联合查询，找出所有工资大于平均工资的记录。
1 select table1.* from Employee as table1, 2 (select deptid ,avg(salary) as avg_salary from Employee group by deptid) as table2 3 where table1.deptid=table2.deptid and table1.salary>table2.avg_salary;
---->查询结果：
（3）查询出各个部门中工资高于本部门的平均工资的员工数和部门号，并按部门号排序
1 select table1.deptid,count(*) from Employee as table1, 2 (select deptid ,avg(salary) as avg_salary from Employee group by deptid) as table2 3 where table1.deptid=table2.deptid and table1.salary>table2.avg_salary 4 group by table1.deptid order by table1.deptid;
----->查询结果：
