Terminology used and implementation features

We imply that the terms “table” and “relation”; “row” and “tuple”; “column”, “attribute”, and “field” are synonyms. Readers interested in terminology subtleties may refer to the fundamental work by C.J.Date [1].

When writing queries online, use SQL Server syntax in case you need specific features not included in the SQL standard (e.g., built-in functions). All scripts in this book have been tested against this DBMS, and it’s also used on the SQL-EX.RU site. Reference information on special aspects of implementation can be found in Part III of this electronic book.

Support for other DBMS is constantly expanding both on the e-book site and on sql-ex.ru. Suffice it to say that to solve the tasks of the learning stage, you can choose not only SQL Server, but also MySQL, PostgreSQL, Oracle. Where the solution of typical tasks within the standard is impossible for one reason or another, examples of queries in the dialects of different DBMS are given.