Practice Self-join (5.5.5) - Structured Query Language (SQL) - Part 2 - Introduction to Database Systems
Students

Academic Programs

AI-powered learning for grades 8-12, aligned with major curricula

Engineering Courses
Professional

Professional Courses

Industry-relevant training in Business, Technology, and Design

Certifications
Games

Interactive Games

Fun games to boost memory, math, typing, and English skills

SELF-JOIN

Practice - SELF-JOIN

Learning

Practice Questions

Test your understanding with targeted questions

Question 1 Easy

What is a self-join?

💡 Hint: Think about relationships within the same dataset.

Question 2 Easy

Why do we use table aliases in a self-join?

💡 Hint: Consider how to avoid confusion with columns.

4 more questions available

Interactive Quizzes

Quick quizzes to reinforce your learning

Question 1

What does a self-join allow a user to do?

Join two different tables
Join a table with itself
Create a new table
Delete records in a table

💡 Hint: Think about joining within the same dataset.

Question 2

True or False: A self-join can only be performed on two different tables.

True
False

💡 Hint: Consider the definition of a self-join.

2 more questions available

Challenge Problems

Push your limits with advanced challenges

Challenge 1 Hard

Construct a SQL query using a self-join to identify pairs of employees who report to the same manager.

💡 Hint: Consider how the relationships are defined through ManagerID.

Challenge 2 Hard

How might you modify your self-join query to include all employees, even those without managers?

💡 Hint: Think about ensuring every employee is listed in your results.

Get performance evaluation

Reference links

Supplementary resources to enhance your learning experience.