Quiz for RIGHT JOIN

Q1: Which of the following is returned by a RIGHT JOIN?

A. All rows from the left table B. Only matching rows C. All rows from the right table and matching from left D. Only unmatched rows

Q2: What does a RIGHT JOIN return?

A. Only matching rows B. All rows from the left table C. All rows from the right table and matching from the left D. All rows from both tables

Q3: In a RIGHT JOIN, if there is no match in the left table, what will be returned?

A. NULLs for the left table B. NULLs for the right table C. Error D. No rows

Q4: Which of these joins returns unmatched rows from the right table?

A. INNER JOIN B. LEFT JOIN C. RIGHT JOIN D. CROSS JOIN

Q5: What keyword is used for RIGHT JOIN in SQL?

A. RIGHT OUTER JOIN B. OUTER RIGHT JOIN C. RIGHT JOIN D. All of the above

Q6: What is the difference between RIGHT JOIN and LEFT JOIN?

A. LEFT JOIN returns all from right B. RIGHT JOIN returns all from right C. No difference D. RIGHT JOIN returns matching only

Q7: Which join returns more rows if the right table has more unmatched records?

A. LEFT JOIN B. RIGHT JOIN C. INNER JOIN D. SELF JOIN

Q8: Which clause determines the joining condition in a RIGHT JOIN?

A. ON B. USING C. JOIN D. WHERE

Q9: Can RIGHT JOIN return NULLs in result?

A. No B. Yes, for unmatched left table rows C. Only for right table D. Only if condition fails

Q10: Which SQL clause allows us to filter results after the join?

A. WHERE B. ON C. JOIN D. USING

Q11: RIGHT JOIN is equivalent to LEFT JOIN if:

A. Tables are switched B. Keys are different C. Indexes used D. None

Q12: Is RIGHT JOIN supported in all SQL dialects?

A. Yes B. No C. Only in PostgreSQL D. Only in MySQL

Q13: Which is more commonly used in practice?

A. LEFT JOIN B. RIGHT JOIN C. Both equally D. None

Q14: In RIGHT JOIN, the join condition is evaluated using:

A. Cartesian product B. Hash function C. Matching keys D. Foreign keys only

Q15: Which of these best describes RIGHT JOIN?

A. All left, matched right B. All right, matched left C. All rows from both D. Only matching rows

Q16: What happens if the ON condition fails for all rows in RIGHT JOIN?

A. Only matched rows returned B. All right table rows with NULLs on left C. No output D. Syntax error

Q17: RIGHT JOIN is also called:

A. INNER JOIN B. OUTER JOIN C. RIGHT OUTER JOIN D. None of these

Q18: What is a key advantage of RIGHT JOIN?

A. Helps in retrieving unmatched rows from right table B. Better performance C. Avoids NULLs D. None

Q19: How many tables are needed to use RIGHT JOIN?

A. 1 B. 2 C. 3 D. Any

Q20: If you want all employees and their departments, even if some employees have no department, which join?

A. LEFT JOIN B. RIGHT JOIN on department C. RIGHT JOIN on employee D. INNER JOIN

Q21: Which SQL clause works with RIGHT JOIN to restrict output?

A. GROUP BY B. HAVING C. WHERE D. LIMIT