Database Properties

A database has the following properties:

  • It is a representation of some aspect of the real world or a collection of data elements (facts) representing real-world information.
  • A database is logical, coherent, and internally consistent.
  • A database is designed, built, and populated with data for a specific purpose.
  • Each data item is stored in a field.
  • A combination of fields makes up a table. For example, each field in an employee table contains data about an individual employee.

 A database can contain many tables. For example, a membership system may contain an address table and an individual member table as shown in Figure 2.2. Members of Science World are individuals, group homes, businesses, and corporations who have an active membership to Science World. Memberships can be purchased for a one- or two-year period, and then renewed for another one- or two-year period.


Figure 2.2. Membership system at Science World.

In Figure 2.2, Minnie Mouse renewed the family membership with Science World. Everyone with membership ID#100755  lives at 8932 Rodent Lane. The individual members are Mickey Mouse, Minnie Mouse, Mighty Mouse, Door Mouse, Tom Mouse, King Rat, Man Mouse, and Moose Mouse.