Introduction to SQL

Welcome to SQLBolt, a series of interactive lessons and exercises designed to help you quickly learn SQL right in your browser.

Since most users will be learning SQL to interact with an existing database, the lessons begin by introducing you to the various parts of an SQL query. The later lessons will then show you how to alter a table (or schema) and create new tables from scratch.

Each lesson will introduce a different concept and end with an interactive exercise. Go at your pace and don't be afraid to spend time experimenting with the exercises before continuing! If you happen to be familiar with SQL already, you can skip ahead using the links in the top-right, but we would recommend you work through the lessons anyways!

By the end, we hope you will be able to have a strong foundation for using SQL in your own projects and beyond.

• Introduction to SQL
• SQL Lesson 1: SELECT queries 101
• SQL Lesson 2: Queries with constraints (Pt. 1)
• SQL Lesson 3: Queries with constraints (Pt. 2)
• SQL Lesson 4: Filtering and sorting Query results
• SQL Review: Simple SELECT Queries
• SQL Lesson 6: Multi-table queries with JOINs
• SQL Lesson 7: OUTER JOINs
• SQL Lesson 8: A short note on NULLs
• SQL Lesson 9: Queries with expressions
• SQL Lesson 10: Queries with aggregates (Pt. 1)
• SQL Lesson 11: Queries with aggregates (Pt. 2)
• SQL Lesson 12: Order of execution of a Query
• SQL Lesson 13: Inserting rows
• SQL Lesson 14: Updating rows
• SQL Lesson 15: Deleting rows
• SQL Lesson 16: Creating tables
• SQL Lesson 17: Altering tables
• SQL Lesson 18: Dropping tables
• SQL Lesson X: To infinity and beyond!