sub query

이런테이블에 급여 평균을 구하여 

 

select avg(SALARY) from EMPLOYEES; 

 

근로자들의 평균임금을 구하는 식이다. 

 

이것을 서브쿼리를 이용하여 평균보다 높은사람 적은사람을 출력해보자 

 

 

 

select  first_name, salary 

  from EMPLOYEES 

  where SALARY >= (select avg(SALARY)  

                  from EMPLOYEES); 

 

이렇게하면된다