Q31.

What is a self join?

Q32.

What is a cross join?

Q33.

What is a full outer join?

Q34.

What is DISTINCT keyword?

Q35.

What is ORDER BY clause?

Q36.

What is LIMIT and OFFSET?

Q37.

What is NULL in SQL?

Q38.

What is the difference between CHAR and VARCHAR?

Q39.

What is CASE statement?

Q40.

What is COALESCE function?