Useful tips on how to work with the textbook
If you have just begun to study SQL(Structured Query Language) is a database computer language designed for the retrieval and management of data in relational database management systems (RDBMS), database schema creation and modification, and database object access control management.SQL language, it is better to begin with Part II, in which the syntax SELECT instruction is analyzed, thereby each chapter contains the numbers of the exercises, which it is recommended to solve for better memorizing of the corresponding material. Further on you should go over to Part I, which will help you to overcome the difficulties in solution of exercises and to understand some more intricate aspects. Studying Chapter 6 one can get acquainted data modification statements. Exercises on these instructions are not considered in the book so far (although subsequently we will certainly include them), as they are rather simple, and more complex structures can be generated only due to use of sub queries. However substantial number of examples provided in the book and solutions of the problems presented on site will enable you to fully learn the suggested material.
If you have a fairly good knowledge of SQL language, you should begin with studying of Part I, referring to Part II just to get the background data on functions of SELECT instruction or to find out about some peculiar features of execution (currently we are using MS Cистема управления реляционными базами данных (СУБД), разработанная корпорацией Microsoft.SQL Server 2012). Studying of other chapters of the book is up to you and depends on level of your competency. We hope you will find them useful for you.
The author advises to begin reading of the book with studying of description of the subject field, i.e. of simulated training database; and with thorough studying of data schemes. Then it is worth to study “fallacious” solution of the exercise and to identify and eliminate the mistake in it, to complete it and then to read explanation. You can check correctness of your understanding using the SQL-EX.RU.
If everything is clear to you without further explanations, you do not need this book. In such a case use the site
There is a service of estimation of efficiency of the queries on the site. Thus you can learn not only how to write valid queries but also how to solve the problem in an optimal way, i.e. in such a way, that executed queries would require less resources of the server.