Filter Results in SQL

Question

Suppose I have a table

  id            value
------        ---------
  10              123
  10              422
  11              441
  11              986
         


        

Answer 1

With mysql 8+ or mariadb 10.2+, you would use the count window function:

select id, value
from (
    select id, value, count(id) over (partition by id) as num_values
    from sometable
) foo
where num_values > 1;