使用with语句重用子查询

 --使用子查询

 select dname,sum(sal) as dept_total from emp,dept where emp.deptno =dept.deptno group by dname

 having sum(sal)>(select sum(sal)*1/3 from emp ,dept where emp.deptno= dept.deptno)

 

 --使用with

 with summary as(

  select dname,sum(sal) as dept_total from emp,dept where emp.deptno =dept.deptno group by dname

 )

 select dname,dept_total from summary where dept_total>(select sum(dept_total)*1/3 from summary)