PostgreSQL. Basics of SQL Language

The educational and practical guide covers the first, basic, part of the course on SQL, created with the participation of the Russian company Postgres Professional. The teaching material is designed for use with the PostgreSQL database management system. It discusses the creation of a working environment, describes data definition languages, and the main operations for querying and modifying data. Examples of transaction usage are provided, with attention given to query optimization methods. The material is accompanied by numerous practical examples. The guide can be used for both self-study and for conducting classes under the guidance of an instructor.