Datalog Educational System


	DES 6.9 and DESODBC 1.2.1 released in November 2025




	Download DES




	DES Playground


	Web site last update: November 25, 2025

The Datalog Educational System (DES) is a deductive database system with Datalog, SQL, Relational Algebra (RA), Tuple Relational Calculus (TRC), and Domain Relational Calculus (DRC) as query languages.

Features in short:


	Free, open-source (LGPL License) Multiplatform, portable Datalog SQL RA TRC DRC Duplicates ODBC Persistence Outer joins Aggregates


	Types Integrity constraints Hypothetical reasoning Fuzzy reasoning Declarative debuggers Graphical tracers Test case generation for SQL Textual API Tabling Stratified negation Full-fledged arithmetic SQL semantic checking