8일차 # 5-8: Join Using (column name)

select department_id, department_name, location_id, city

  from departments 

  join locations

  using (location_id);

<Oracle Syntax>

  select department_id, department_name, departments.location_id, city

  from departments, locations

  where departments.location_id = locations.location_id;

  cf.)  natural join, join using 에선 

조인대상이 되는 컬럼에 테이블 이름을 쓸 수 없습니다.

  select department_id, department_name, departments.location_id, city

  from departments

  natural join locations;

  select department_id, department_name, departments.location_id, city

  from departments 

  join locations

  using (location_id);

  select department_id, department_name, location_id, city

  from departments 

  join locations

  using (departments.location_id);