D4 is a computer language used in Dataphor, a truly Relational Database Management System. A computer language is a language used by, or in association with, computers. ... Dataphor is a truly relational database management system, unlike SQL which actually inherently violates several principles of the relational database management model. ... A relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by Edgar F. Codd. ...

Syntax

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. Pascal is an imperative computer programming language, developed in 1970 by Niklaus Wirth as a language particularly suitable for structured programming. ... This article or section relies largely or entirely upon a single source. ... Delphi is the primary programming language of Borland Delphi. ...

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. A Data Definition Language is a computer language for defining data. ... Data Manipulation Language (DML) is a family of computer languages used by computer programs or database users to retrieve, insert, delete and update data in a database. ... In computer science, imperative programming, as opposed to declarative programming, is a programming paradigm that describes computation in terms of a program state and statements that change the program state. ...

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. Please see Relational database Relational algebra This is a disambiguation page: a list of articles associated with the same title. ... Declarative programming is a term with two distinct meanings, both of which are in current use. ... SQL (commonly expanded to Structured Query Language — see History for the terms derivation) is the most popular computer language used to create, modify, retrieve and manipulate data from relational database management systems. ...

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. SQL (commonly expanded to Structured Query Language — see History for the terms derivation) is the most popular computer language used to create, modify, retrieve and manipulate data from relational database management systems. ... Relational algebra, an offshoot of first-order logic, is a set of relations closed under operators. ...

Imperative Language

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.

History

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 disovering Tutorial D and The Third Manifesto, Alphora has used The Third Manifesto as a guide in making Dataphor and D4. Dataphor is a truly relational database management system, unlike SQL which actually inherently violates several principles of the relational database management model. ... Tutorial D is an example of a truly relational database query language, developed by Christopher J. Date and Hugh Darwen and described in The Third Manifesto. ... The Third Manifesto (1995) is Christopher J. Dates and Hugh Darwens proposal for future relational database management systems that would avoid Object-Relational Impedance Mismatch between object-oriented programming languages and RDBMSs by fully supporting all the capabilities of the relational model. ...

References

• D4 Language Guide
• Purpose of D4
• D4 BNF