Professional Courses
Industry-relevant training in Business, Technology, and Design to help professionals and graduates upskill for real-world careers.
Categories
Interactive Games
Fun, engaging games to boost memory, math fluency, typing speed, and English skills—perfect for learners of all ages.
Typing
Memory
Math
English Adventures
Knowledge
Enroll to start learning
You’ve not yet enrolled in this course. Please enroll for free to listen to audio lessons, classroom podcasts and take practice test.
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.
Solve 2 more questions and get performance evaluation
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