Course

SQL Subqueries

In this course, you’ll learn how to nest queries inside other queries.

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Part of the SQL, and Business Analyst (Power BI) paths.

4.8 (359 reviews)

7,035 learners enrolled in this course.

Intermediate friendly
6 hours
Self paced
6 lessons
1 project

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Adam Zabrodski

Data Science Manager @ Later

SQL Subqueries

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Course overview

A subquery is a query nested inside another query. Subqueries are useful to data practitioners for scaling and making more powerful queries. The main reason we have subqueries is the need to combine information from multiple tables. Information in a relational database isn’t stored in a single table; it’s shared between several tables.

In this course, you’ll learn various types of subqueries, how to use them, and why they are so valuable: scalar subquery, multi-rows subquery and multi-columns subquery. You’ll also learn how to write common table expressions in SQL.

Best of all, you’ll learn by doing — you’ll practice and get feedback directly in the browser.

Key skills

Nesting a query inside another query
Employing different types of subqueries
Employing common table expressions
Scaling your project with complex queries

Course outline

SQL Subqueries [6 lessons]

Scalar Subqueries in SQL 1h

Lesson Objectives

Extract a single value from a subquery
Employ a single value subquery in your queries
Identify why subqueries are useful

Multi-row and Multi-column Subqueries in SQL 1h

Lesson Objectives

Extract multiple rows from a subquery
Extract multiple columns from a subquery
Scale your project with multi-row subqueries

Nested and Correlated Subqueries in SQL 1h

Lesson Objectives

Nest a subquery inside another subquery
Write dependent subqueries
Write effective queries

Common Table Expression in SQL 1h

Lesson Objectives

Write Common Table Expressions (CTEs)
Write Recursive Common Table Expression

Views in SQL 1h

Lesson Objectives

Explain the concept and application of views in SQL
Create views
Query views
Create views from views
Drop views

Guided Project: Customers and Products Analysis Using SQL 1h

Lesson Objectives

Expand your portfolio using real-world data

Projects in this course

Customers and Products Analysis Using SQL

For this project, you’ll step into the role of a data analyst at a scale model car company. You’ll use SQL skills like joins and subqueries to explore a sales database and provide data-driven answers to key business questions about inventory, customers, and marketing.

View Project

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