Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. D4 is a computer language used in Dataphor, a relational database management system. Alphora, the creators of D4, have given it a Pascal like syntax. Sample code in D4 made by Alphora is usually written in UpperCamelCase, which is also widely used in Pascal and Delphi systems. Like most query languages, D4 has a Data Definition Language (DDL) and a Data Manipulation Language (DML). D4 also has an Imperative Language for procedural code. The DDL for Dataphor bears many similarities to other DBMSs, but with an obviously Pascal-like twist. Many of the allowed DDL operations, like constraints allow relational declarative statements to be used, which many believe is superior to the procedural style operations used in SQL ex: create,drop,truncate,alter.

Данное издание не является оригинальным. Книга печатается по технологии принт-он-деманд после получения заказа.