SQLBolt, interactive lessons in the browser

SQLBolt is a free tutorial at sqlbolt.com. Each lesson introduces one idea and ends with an exercise you run in the browser. It starts with SELECT and constraints, then joins, nulls, aggregates, and later insert, update, delete, and table changes.

What it is for

People who need the language in order, not a puzzle. You can skip ahead if you already write SQL, but the value is the sequence: one concept, then a task that will not let you continue until it is right.

The early tables are simple on purpose. Pixar films, not a warehouse. That is a teaching choice. The syntax is still the syntax you will use on SQL Server.

When I point people at it

When someone on an operations team needs to read a query and has never written SELECT. SQLBolt is shorter than a course and does not ask for a login.

I do not use it as interview prep. For that I want messier data. For the first week of SQL, a lesson with an exercise is the right shape.