GQL learning guide · Dominik Tomaszuk

ISO/IEC 39075: The GQL Standard Explained

ISO/IEC 39075:2024 is the international standard for Graph Query Language. Its formal title is Information technology: Database languages: GQL. The first edition was published in April 2024.

What does the standard specify?

The specification covers the structures of property graphs and operations for creating, querying, maintaining and controlling graph data. It defines both syntax and semantics: how statements are written and what they mean. See the ISO catalogue record for the publication, preview and related corrections.

How the book helps you read it

GQL Essentials combines a library example with a mathematical account of the data model and query evaluation. Start with the concrete example, then read Data Model to connect nodes, edges and properties to formal definitions.

Continue to Patterns and Matching for bindings and matching, and Algebra of Binding Tables for query composition. These explain the mechanics behind a query result rather than only its notation.

What about schemas and updates?

Read Types and Schemas for graph structure and Data Modification for updates. The chapters on transactions, authorization and diagnostics develop the book's formal treatment of execution behavior. Proposed extensions are discussed separately in Future Enhancements.

Using a standard with a real database

A standard is a specification, while a database implements a particular set of features. Before running examples, check the implementation's conformance statement and feature documentation. Record the database version when comparing behavior. The book is an independent educational text; use the ISO publication for normative requirements.

For a shorter introduction, read What is GQL? or follow the beginner tutorial. The bibliography collects the standards and research cited in the book.