In Chapter 2, The Other Way Around – Database First Approach, we re-engineered the existing database using Entity Framework's Database-First approach. Let's now start to understand the terminologies and conventions used in relationships.

Entities are of no use if we don't give them an identity. The relationship terms we will be exploring in this chapter will provide an identity for the entities, which not only describes them, but also helps us in creating relationships between different entities.

The topics we will cover in this chapter are:

• Understanding relationship terms:
  • Data models
  • Principal entity
  • Principal key
  • Dependent entity
  • Foreign key
  • Navigation property
• Conventions in a relationship:
  • Fully-defined relationships
  • No foreign key property
  • Single navigation property
  • Foreign key
  • Inverse property