Free course · no setup

Learn SQL by writing real queries

SQL is how you ask questions of data. Every app, dashboard and company report sits on a database, and SQL is the language that talks to it. On Codeglass you write real queries from the first minute: each lesson teaches one idea, then your hands do the typing and we check the query the way a database would read it.

13 lessons · 195 XP · checked line by line

What you will learn

  1. 01What is a database?
  2. 02Show me everything
  3. 03Just one column
  4. 04Two columns, one comma
  5. 05Only the rows that qualify
  6. 06Matching text
  7. 07Strict: quotes mean text
  8. 08Put them in order
  9. 09Biggest first
  10. 10Just the top few
  11. 11Count, don't list
  12. 12Two tests at once
  13. 13Level 2 boss: a real question

Questions beginners ask

Do I need to know anything first?

No. The first lesson explains what a database is from scratch, then you write your first SELECT.

Do I need to install a database?

No. Codeglass runs in your browser. You type queries, we check them line by line.

What will I be able to do?

Pull exactly the rows you want with WHERE, sort and limit results, aggregate with COUNT, SUM and AVG, group with GROUP BY, and combine tables with JOINs.

Is it free?

Yes. Sign in with an email code and start. No card, no trial.

Your first SQL lesson takes five minutes

Sign in with an email code. No password, no card, no install.

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