Joe Celko's Thinking in Sets

The biggest obstacle to becoming an expert SQL programmer is unlearning procedural programming. But saying that does not show you how to do things in a declarat... » 

The biggest obstacle to becoming an expert SQL programmer is unlearning procedural programming. But saying that does not show you how to do things in a declarative language when you have been thinking in the files and procedural code of a C++ program. Hence this book, with actual techniques and an explanation of the thought processes that lead to them. The techniques are classified as Auxiliary, Temporal, and Virtual tables, and by learning how to use them you will simplify application development, avoid programming, and take one more step to master SQL! Auxiliary tables: are used to compute functions and other values by joins rather than by procedural programming. There are many common examples, such as look-up tables for codes, functions that cannot be computed easily, and defining constraints. Temporal tables: are those that support temporal queries, historical data and audit information. Joe places special emphasis on temporal programming because the topic is complicated in both the concepts and the implementations. Virtual tables: are materialized (or appear to be materialized) by the SQL engine. They do not exist in the schema like base tables. They come in several «