Abstract
The university textbook guides the reader through the design and implementation of databases. The reader will be acquainted with the necessary theory supplemented by a number of practical examples.
The core of the textbook are relational database systems, which, despite predictions, still manage the vast majority of data. However, the reader will be also acquainted with new trends in the database community, especially NoSQL databases.
One comprehensive example goes through the entire textbook. We will start with a conceptual model and gradually introduce its implementation in a relational database engine.
The explanation of the SQL query language will then take place on the same schema. In the second edition, we also offer a chapter devoted to graph databases, completed by a simple example of finding a path in a graph in the query languages SQL, Cypher and Gremlin.
The textbook includes freely available electronic appendices with examples, so the reader will be able to try the material directly. The appendices include SQL scripts for creating a database and populating data for PostgreSQL and Oracle database engines, SQL codes for all the examples discussed, as well as source codes and data for an example of graph databases.