1965. Employees With Missing Information

https://leetcode.com/problems/employees-with-missing-information/

Employees With Missing Information - LeetCode

select * from (
select a.employee_id
from Employees as a
left outer join Salaries as b
on a.employee_id = b.employee_id
where b.employee_id is null
union
select b.employee_id
from Employees as a
right outer join Salaries as b
on a.employee_id = b.employee_id
where a.employee_id is null) as a
order by a.employee_id asc

best

SELECT a.employee_id 
from(
SELECT employee_id from employees
union all
SELECT employee_id from salaries) as a
GROUP BY employee_id
Having count(employee_id) = 1
order by employee_id asc

References

https://gywlsp.github.io/mysql/5/

MySQL에서 테이블 inner join, outer join 하는 법