I recommend trying out https://www.sql-ex.ru https://www.sql-ex.ru which has some good exercises which can trip up a lot of people. I have used quite a few ques

I recommend trying out https://www.sql-ex.ru https://www.sql-ex.ru which has some good exercises which can trip up a lot of people. I have used quite a few questions from here as an interviewer. Going through it completely is a solid foundation for tackling SQL at work. As a baseline, if one can solve https://www.jitbit.com/news/181-jitbits-sql-interview-questions/ https://www.jitbit.com/news/181-jitbits-sql-interview-questi... then you can be confident you can nail entry-mid level positions involving SQL.