Every now and then I see something like this: select u.* from users u where 0 = (select count(*) from addresses a where a.user_id = u.id); and it kinda pains me. So figured, I'll write about what is the problem with it, and how to avoid such constructs. Lets consider what went through someones mind … Continue reading "SQL best practices – don’t compare count(*) with 0"
