Quiz on SQL LEFT JOIN

What does a LEFT JOIN return?

What happens when there’s no matching row in the right table?

Which keyword is equivalent to LEFT JOIN?

Choose the correct syntax for LEFT JOIN:

What is the output if no rows in the right table match?

If the left table has 4 rows and right has 2 matching rows, how many rows are returned in LEFT JOIN?

Which clause filters records after LEFT JOIN?

What happens if WHERE filters for right table column (e.g., WHERE B.id IS NOT NULL) after LEFT JOIN?

What does this query return?

SELECT * FROM employees e LEFT JOIN departments d ON e.dept_id = d.id;

LEFT JOIN is helpful in which scenario?

Which JOIN keeps unmatched rows from both sides?

Which of the following will return customers who haven’t placed any orders?

Which JOIN returns fewer rows in general?

What does the ON clause do in LEFT JOIN?

What will this query return?

SELECT * FROM books LEFT JOIN authors ON books.author_id = authors.id;