Practice Questions
Test your understanding with targeted questions related to the topic.
Question 1
Easy
What does INNER JOIN do in SQL?
💡 Hint: Think about how you combine data across related tables.
Question 2
Easy
Define an aggregate function.
💡 Hint: Consider what you might want to find the total or average of.
Practice 4 more questions and get performance evaluation
Interactive Quizzes
Engage in quick quizzes to reinforce what you've learned and check your comprehension.
Question 1
What type of join returns all matching records?
- INNER JOIN
- LEFT JOIN
- RIGHT JOIN
💡 Hint: Think about the relationship enforced by the join.
Question 2
True or False: LEFT JOIN returns only matching rows.
- True
- False
💡 Hint: Visualize the data returned in both tables.
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Challenge Problems
Push your limits with challenges.
Question 1
Create a SQL query using an aggregate function to find how many users have made orders in total.
💡 Hint: Think about how you can count unique entries.
Question 2
Write a SQL query that retrieves users who have not made any orders, using a subquery.
💡 Hint: Consider how to filter non-participating users based on another table.
Challenge and get performance evaluation