2.2 · Lesson

The Data Domain and the Graph Model

In the last lesson, you learned how a set of data is organized into a domain model for human understanding, and then mapped to an application domain model. In some cases, the application domain model also needs to be mapped to a database model.

While this can be a one-to-one mapping where all three models are the same, it often isn't. This is because each model must fit the Full definition for constraint (opens in a new tab)A rule the database enforces on every node or relationship with a given label or type, rejecting any write that breaks it. of the system it is designed for. The human domain model must be easily translatable to stakeholders, business analysts, and developers. The application domain model must fit the constraints of the chosen programming language. The database model must fit the constraints of data types, Full definition for relationship (opens in a new tab)A named, directed connection between two nodes. Every relationship has a type, a start node and an end node. syntax, and efficient storage and query retrieval.