SQL Questions to solve

Job ID: 33070366

Budget: $10 – $30 USD

Hi, I have three SQL questions, and I need a code that can solve properly this 3 questions.
A persons that knows SQL weel should be able to solve them in 20 or 30 minutes.
I need to receive proff that the code works.
Three questions will be
Related categories: SQL MySQL Microsoft SQL Server SQLite Coding