Skip to main content

Course

Joining Data in SQL

Basic2 hr 30 min

Level up your SQL knowledge and learn to join tables together, apply relational set theory, and work with subqueries.

Sql2 hr - 3 hr3,950 XP330K+Statement of accomplishment

Create Your Free Account

Continue with Google
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

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

Curriculum

Course outline

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.

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.

S

Joining Data in SQL

Course
Complete

Earn Statement of Accomplishment

Enroll Now

Grow your data skills with DataCamp for Mobile

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

Joining Data in SQL | DataCamp