O'Reilly logo

Essential ADO.NET by Bob Beauchemin

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

1.3. The Relational Model

Relational databases use the relational data model popularized by E. F. Codd and C. J. Date. The relational model represents data as entities. An entity is a real-world object, such as a customer or an order. Each entity is represented by a row in a table. Rows are referred to as tuples and consist of a series of attributes (columns). Entities have state, which consists of the values of the attributes (columns). Each column has a single value drawn from a domain of appropriate values.

Most relational databases have the concept of a distinct type, usually a restriction of a simple type such as integer, which comes close to (but does not exactly correspond to) SQL-99's definition of a domain of values. An example of a ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required