Domain Model Keys

Keys are very important part of relational database model.

Domain model keys. Keys are attributes or sets of attributes that uniquely identify an entity within its entity set. The domain entities could look like this. Public string firstname get.

Associations an association is a relationship between two or more domain classes. Domain constraints are user defined data type and we can define them like this. They are used to establish and identify relationships between tables and also to uniquely identify any record or row of data inside a table.

Public employee public string employeeid get. Attributes an attribute is the description of a named slot of a specified type in a domain class. A domain is a unique set of values permitted for an attribute in a table.

We are using the code first approach so we start by defining our domain objects as pocos plain old clr objects. John mullins developed the seven domains model and published it in his 2003 book the new business road test the model helps you explore a business idea from a variety of angles including factoring in the knowledge and attitudes of your team. A domain model logically represents the business concepts to be fulfilled by the system and how they relate to one another.

You start with a visual model and entity framework generates both the database and code. But if your application is large and complex you should definitely choose rich model instead of anemic one and thus don t use ids in your domain classes. A key can be a single attribute or a group of attributes where the combination may act as a key.

A domain model is a system of abstractions that describes selected aspects of a sphere of knowledge influence or activity a domain. No two entities may agree in their values for all of the attributes that constitute a key. Heavy ids usage is common for anemic model.