コピペ: sql problem "1965. Employees With Missing Information" #update 2

形式

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投稿日時

2022-06-27 05:01

公開期間

無期限

 Given the table Employee (employee_id, name) and Salary (employee_id, salary) with some extra info that aren't crucial, give the list of employee_id that do not have names or salaries in ascending order.
 
 
 select inner_select.employee_id from (
     select employee_id from Employees where employee_id not in (select employee_id from Salaries)
     union
     select employee_id from Salaries where employee_id not in (select employee_id from Employees)
 ) as inner_select order by inner_select.employee_id asc;
 
 I think it could be improved to be more efficient. One idea is to join Employee and Salary on the employees that are in both and then take a subtraction between all the employee_id and those in the join. But that operation may cost quite a bit as well (a join is not cheap and the diff is not cheap too).
 
 Idee it seems that it is possible to improve quite a bit.
 "Runtime: 596 ms, faster than 43.59% of MySQL online submissions for Employees With Missing Information.
 Memory Usage: 0B, less than 100.00% of MySQL online submissions for Employees With Missing Information."