Finally

The author continues to work on the book, adding new materials and editing existing ones. In particular, chapters have been added on the Data Definition Language (DDL) and new syntax constructs of queries that appeared in the latest versions of the SQL standard and are supported by implementations.

It is planned to write about the basics of table normalization and query optimization. The author will gratefully accept your constructive comments and suggestions, which you can send to the email address sqlex.moiseenko[@]yandex[DOT].com.