GNU Sqltutor is a web based interactive tutorial of Structured Query Language (SQL). You can try Sqltutor online from
First, a tutorial must be selected from the opening page and started. A series of tutorial questions follows in a simple dialog. When finished Sqltutor displays final evaluation with the review of all questions asked during the session together with user's SQL queries and correct answers for wrong solutions.
Sqltutor is implemented on the top of a relational database system PostgreSQL. The project consists in part of a C++ program of the same name sqltutor released under the GNU General Public License (GNU GPL). The sqltutor program is a CGI script that selects SQL questions from its database, checks the answers and evaluates the final score. The second part of the project is a free collection of SQL questions and answers representing SQL tutorials. Sqltutor enables to run one or more tutorials in different languages from a single database.
Sqltutor was inspired by an interactive tutorial SQLzoo by Andrew Cumming from the School of Computing, Napier University, Edinburg, UK. Implementation of the database and the sqltutor program is not dependent neither derived from the SQLzoo tutorial.
English SQLzoo tutorial distributed with Sqltutor is based on the collection of SQL questions and answers and datasets from http://sqlzoo.net/. We would like to thank Andrew Cumming for his kind approval to use his data and tutorials in our project.