If you're looking for a book that get will get you up to speed with using databases quickly this isn't it. You need to wade through several chapters before you have even have the basics grasped and there is no 'tutorial' chapter as such. The text is cluttered with reiterations of the same facts at a level of detail entirely inappropriate for an introductory book.
More seriously, coverage of SQL is relegated to final subsections of chapters rather than being directly next to the theory, which would aid those learning SQL. Although, as the author points out, no current SQL implementations are true relational database systems, SQL is still the de facto industry standard so this style is counter-productive. Instead, the author's own Tutorial D language is used throughout. Even worse, Tutorial D is explicitly chosen over the more common mathematical notation for the Relational Algebra and Predicate Calculus, obfuscating the simplicity of the relational model, especially for mathematicians.
Overall the style of language comes across as rambling and ranting. On the plus side, if you have the time to look, all the information is there and there are many good references to the literature.