SQL JOIN Types: INNER, LEFT, RIGHT, FULL

1. A FULL JOIN is supported in all SQL databases including MySQL.

True

False

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5. Which JOIN type is used when you need to find customers who have never placed an order?

INNER JOIN

LEFT JOIN

RIGHT JOIN

CROSS JOIN

6. In a FULL JOIN, a row with no match in either table will still appear in the result set.

True

False

Submit

8. What is the primary difference between a RIGHT JOIN and a FULL JOIN?

RIGHT JOIN includes the left table; FULL JOIN does not

FULL JOIN includes unmatched rows from both tables; RIGHT JOIN only from the right

They are functionally identical

RIGHT JOIN uses different syntax

9. In a LEFT JOIN, if there are 100 rows in the left table and 50 matching rows in the right table, the result set will contain exactly 50 rows.

True

False

10. Which JOIN type typically returns the smallest result set?

INNER JOIN

LEFT JOIN

RIGHT JOIN

FULL JOIN

11. What does an INNER JOIN return?

Only rows with matching values in both tables

All rows from the left table plus matches from the right

All rows from both tables regardless of matches

Only rows from the first table listed

12. When would you use an INNER JOIN instead of a LEFT JOIN?

When you need all rows from the left table

When you only want rows with matching values in both tables

When the right table has more rows

When you want to preserve unmatched rows

Submit

15. Which JOIN type combines all rows from both tables, filling in NULLs where matches don't exist?

INNER JOIN

LEFT JOIN

FULL JOIN

NATURAL JOIN

16. A LEFT JOIN returns unmatched rows from the right table as NULL.

True

False

17. An INNER JOIN will produce NULL values in the result set.

True

False

18. What is a FULL JOIN also known as?

COMPLETE JOIN

OUTER JOIN

FULL OUTER JOIN

TOTAL JOIN

19. A RIGHT JOIN preserves all rows from which table?

The table on the left side of the JOIN keyword

The table on the right side of the JOIN keyword

Whichever table has fewer rows

Both tables equally

20. Which JOIN type includes all rows from the left table and matching rows from the right?

INNER JOIN

LEFT JOIN

RIGHT JOIN

CROSS JOIN

DataSys+ INNER LEFT RIGHT and FULL JOIN Types Quiz

1. A FULL JOIN is supported in all SQL databases including MySQL.

2.

What first name or nickname would you like us to use?

2. When joining tables with multiple matching keys, you must use multiple ____ conditions.

3. LEFT and RIGHT JOINs are collectively referred to as ____ JOINs.

4. A CROSS JOIN produces a ____ product of the two tables.

5. Which JOIN type is used when you need to find customers who have never placed an order?

6. In a FULL JOIN, a row with no match in either table will still appear in the result set.

7. The ON clause in a JOIN specifies the ____ condition between the tables.

8. What is the primary difference between a RIGHT JOIN and a FULL JOIN?

9. In a LEFT JOIN, if there are 100 rows in the left table and 50 matching rows in the right table, the result set will contain exactly 50 rows.

10. Which JOIN type typically returns the smallest result set?

11. What does an INNER JOIN return?

12. When would you use an INNER JOIN instead of a LEFT JOIN?

13. A RIGHT JOIN is functionally equivalent to a LEFT JOIN with the table order ____.

14. If a value exists in the left table but not the right table during a LEFT JOIN, the corresponding right table columns will contain ____.

15. Which JOIN type combines all rows from both tables, filling in NULLs where matches don't exist?

16. A LEFT JOIN returns unmatched rows from the right table as NULL.

17. An INNER JOIN will produce NULL values in the result set.

18. What is a FULL JOIN also known as?

19. A RIGHT JOIN preserves all rows from which table?

20. Which JOIN type includes all rows from the left table and matching rows from the right?