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.
Data definition language
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.
Data manipulation language
The DML syntax at first glance may appear to be similar to SQLs syntax, but because of D4's closer ties to relational algebra, the syntax has a cleaner definition, and most users greatly prefer it over SQL.
The Imperative Language in D4 is remarkably similar to Pascal in many respects. The largest distinction being that D4 also allows DDL and DML statements to be run in regular procedural code.
D4 was named after the similar sounding Dataphor, the system that uses the language. It was some time after these names were decided that Alphora discovered Tutorial D, and the coincidence it had with that name. Since discovering Tutorial D and The Third Manifesto, Alphora has used The Third Manifesto as a guide in making Dataphor and D4.
In early 2008, the Alphora name and the Dataphor product were acquired by Database Consulting Group LLC, founded by the original developers of Dataphor, and was re-licensed as open source.
- Tutorial D
- The Third Manifesto