Skip to main content
HomeSQL

Course

Joining Data in SQL

BasicSkill Level
4.8+
20,380 reviews
Updated 04/2026
Level up your SQL knowledge and learn to join tables together, apply relational set theory, and work with subqueries.
Start Course for Free
SQLData Manipulation
2 hr - 3 hr
3,950 XP
310K+
Statement of Accomplishment

Create Your Free Account

or

By continuing, you accept our Terms of Use, our Privacy Policy and that your data is stored in the USA.

Loved by learners at thousands of companies

Group

Training a Team?

Try for Business

Course Description

Joining data is an essential skill in data analysis, enabling you to draw information from separate tables together into a single, meaningful set of results. In this comprehensive course on joining data, you'll delve into the intricacies of table joins and relational set theory, learning how to optimize your queries for efficient data retrieval.

Understand Data Joining Fundamentals

You will learn how to work with multiple tables in SQL by navigating and extracting data from various tables within a SQL database using various join types, including inner joins, outer joins, and cross joins. With practice, you'll gain the knowledge of how to select the appropriate join method.

Explore Advanced Data Manipulation Techniques

Next up, you'll explore set theory principles such as unions, intersects, and except clauses, as well as discover the power of nested queries in SQL. Every step is accompanied by exercises and opportunities to apply the theory and grow your confidence in SQL.

Prerequisites

Intermediate SQL
1

Combining Data Vertically

  • Stacking Rows with UNION

    Stack rows from multiple tables into a single unified result, and know when stacking (rather than joining) is the right approach for combining data.

Start Course for Free
2

Combining Data Horizontally

  • Keeping All Rows with LEFT JOIN

    Enrich a base table with additional data without losing any rows, and understand when a left join is the right choice — specifically, when not every row in your primary table has a match in the other table.

  • Keeping Matching Rows with INNER JOIN

    Combine only the rows that match across tables, understand how inner joins differ from left joins, and choose between them based on whether unmatched rows matter to your analysis.

  • Joining on Multiple Columns

    Join tables accurately when no single column uniquely identifies matching rows, and recognize the consequences of choosing incorrect join columns.

Joining Data in SQL
Course
Complete

Earn Statement of Accomplishment

Add this credential to your LinkedIn profile, resume, or CV
Share it on social media and in your performance review
Enroll Now

Don’t just take our word for it

*4.8
from 20,380 reviews
82%
16%
1%
0%
0%

Omar

Aimee

Vaibhav

FAQs

Is this course suitable for beginners?

Yes, this course is suitable for beginners. The concepts are introduced simply and there are many opportunities to practice throughout.

Who will benefit from this course?

This course is beneficial for anyone who works with databases and wants to become more proficient in SQL. It would be especially beneficial to data scientists, software engineers, business analysts and application programmers.

Will I receive a certificate at the end of the course?

Yes, you will receive a certificate at the end of the course.

Will I learn about semi-joins and anti-joins in this course?

Yes, you will learn about semi-joins and anti-joins in the closing chapter of the course after learning about inner and outer joins.

What is an inner join in SQL?

An inner join is a type of join operation that combines the data from two tables into a single table. The result table will contain only those rows that have a match based on the joined columns.

How will this course help me use set theory in SQL?

This course will help you become familiar with set theory operations in SQL, such as UNION, UNION ALL, INTERSECT and EXCEPT clauses. You will also explore the ways in which set theory operations differ from join operations.

What types of joins will I learn in this course?

In this course, you will learn about inner joins, outer joins, cross joins, and self-joins.

Join over 19 million learners and start Joining Data in SQL today!

Create Your Free Account

or

By continuing, you accept our Terms of Use, our Privacy Policy and that your data is stored in the USA.

Grow your data skills with DataCamp for Mobile

Make progress on the go with our mobile courses and daily 5-minute coding challenges.