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Our notes on SQLZoo

We wrote these notes when we read the SQLZoo site for our SQL comparisons. For each note, you see the day of our check and a link to the page that we read.

SQLZoo price and plans

  • Free. We found no paid plan on the site. Checked October 12, 2026 (source)

SQLZoo free use

  • All tutorials and exercises are free. Checked October 12, 2026 (source)

SQLZoo account

  • You need no account to start. Checked October 12, 2026 (source)

SQLZoo query check and help

  • You write each query in the browser. SQLZoo compares your result with the expected rows, for example "Wrong answer. Too few rows." We ran a two-query test with no account. For a rewrite with the same rows, with OR in place of IN and in a different order, SQLZoo showed "Correct answer". For a result one row short, SQLZoo showed "Wrong answer. Too few rows." Checked October 17, 2026 (source)
  • SQLZoo gives some questions a short hint behind a link, for example "HELP:How to calculate per capita GDP". In the 13 tutorials, we found a hint on 14 of the 132 questions. On each question, after a wrong answer, SQLZoo shows a message, for example "Wrong answer. Too many rows.", and the link "Show what the answer should be...". This link shows the expected result rows, not the query. SQLZoo also has an answer mode, "Cheat mode": if you add "?answer=1" to the address of a tutorial, SQLZoo puts the answer query in each query box. We found that the answer mode works on all 13 tutorials, but SQLZoo shows a link to it for only 2 tutorials. Checked October 22, 2026 (source)

SQLZoo SQL topics

  • SQLZoo has tutorials on GROUP BY, joins, self joins, window functions, and SELECT within SELECT (subqueries). Checked October 12, 2026 (source)
  • In its tutorial list, SQLZoo has no tutorial on common table expressions (CTEs, WITH). In the 13 numbered tutorials, we found no question and no answer query with a WITH clause. Checked October 22, 2026 (source)

SQLZoo SQL engines

  • You choose the engine: MySQL, PostgreSQL, Microsoft SQL, or Oracle. MySQL is the default. Checked October 20, 2026 (source)

SQLZoo content and size

  • 13 numbered tutorials, plus quizzes and assessments of 15 questions each. Checked October 12, 2026 (source)
  • We found no guided project. SQLZoo has assessments of 15 questions on one database each, for example "Guest House". Checked October 15, 2026 (source)
  • SQLZoo has 13 numbered tutorials. Ten have the numbers 0 to 9. SQLZoo gives the other three the numbers "8+", "9-" and "9+" (Numeric Examples, Window function, and COVID 19). In these 13 tutorials, we counted 132 questions. The quizzes, the assessments and the two DDL tutorials are not in this count. Checked October 24, 2026 (source)

SQLZoo certificate

  • SQLZoo offers no certificate. Checked October 12, 2026 (source)

SQLZoo updates

  • On the tutorial page, SQLZoo shows the line "last modified on 25 July 2026". This is a dated wiki edit. Checked October 20, 2026 (source)

SQLZoo strengths and limits

  • SQLZoo checks window function exercises too, and you can run each exercise on four engines. Checked October 12, 2026 (source)
  • Each tutorial is a list of questions with short notes. You get no full lesson on the idea before the questions. Checked October 12, 2026 (source)

SQLZoo in our SQL comparisons