Blog 4.4 - Entity Relationship Diagram

In this Entity Relationship Diagram, there are three main Entities : Customer, Invoice, and Product.
Within each entity there are different attribute types such as Name, but a specific name such as John Smith is an Attribute. Each entity can be described as a table each containing rows and columns, the rows being records and columns being attributes. Each attribute type has its own data type dependent upon the type of information, such as name being text. The customer entity, contains attribute types such as Name, Address, and gender. It also contains a customer key, and ID number that is specific to the individual, such that it can be referred to later. The Product entity contains attribute types such as the type of product, the price and the Product key. Like the customer key it is a reference key used to compare and correlate data in other entites.