Database Model

The DP4 database management system is based on the relational database model. In a relational database, the entities in a system are represented as tables. A table is a two-dimensional array in which the columns define the fields in a record, and the rows represent different records.

This topic is divided into the following sub-topics:

• Entity Modelling
• Entity Relationships
• Table Definition
• Field Definition
• Primary Key
• Relationships Between Tables
• Referential Integrity
• Field Roles
• Data Types
• Range of Occurrences
• Data Dictionary Plan
• Automatic Increment of Key Values
• Indexes
• Record Sequence and Key Precedence