Q&A about the site for science fiction and fantasy enthusiasts
with p1 as (select owneruserid from posts where year(creationdate) = 2010), p2 as (select owneruserid from posts where year(creationdate) = 2015) select distinct top 20 displayname from users join p1 on users.id = p1.owneruserid join p2 on users.id = p2.owneruserid;