Plz anything more to learn under Sql

Question

I just finished solo learn sql course. Plz is there anything more to learn under sql and how do I improve in it?

Answer 1

yes , foreign key is absent here , U have to learn abt that also
//can't challenge in sql for now @Sylar

Answer 2

You should challenge others. It doesn't matter whether lose or win, point is you can improve your skill by learning your mistakes when you lose a challenge.