[SolveSQL] 멘토링 짝꿍 리스트

문제 URL : https://solvesql.com/problems/mentor-mentee-list/

https://solvesql.com/problems/mentor-mentee-list/

 

*문제 저작권으로 인하여 직접 작성한 쿼리문만 첨부

 

select YB.employee_id as mentee_id, 
       YB.name as mentee_name,
       OB.employee_id as mentor_id,
       OB.name as mentor_name

from employees YB cross join employees OB

where YB.join_date between '2021-09-01' and '2021-12-31'
and OB.join_date <= '2019-12-31'
and YB.department != OB.department

order by mentee_id, mentor_id

 

두 테이블 간의 결합에 있어 가능한 모든 조합을 확인할 수 있는 CROSS JOIN 사용