When should I use value objects?

When should I use value objects?

Value Objects can be especially useful as a means for describing concepts in an application that have intrinsic rules but which are not themselves entities. In many applications, some concepts that are described as entities would be better off implemented as value objects.

How do you store value objects in a database?

Persisting Value Objects

1. Inline Value Object’s Fields to Entity’s Table.
2. Create Database Table for each of Value Object Type and Represent Data as Field.
3. Serialize the Value Object and Store in Field in Entity’s Table.
4. Combined RDMS and Document Database Approach.
5. Use a Document Database.

Which is an example of value basic object?

Examples of value objects are objects representing an amount of money or a date range. Being small, one can have multiple copies of the same value object that represent the same entity: it is often simpler to create a new object rather than rely on a single instance and use references to it.

Can we have more than one value object of same type in a single entity?

Firstly, when you have two Entities with the same attributes, these two objects are not the same because they have two different identities. However, when you have two Value Objects with the same values, these two objects do have equality and can therefore can be interchanged freely.

How to persist value objects as owned entity types?

Persist value objects as owned entity types in EF Core 2.0 and later Even with some gaps between the canonical value object pattern in DDD and the owned entity type in EF Core, it’s currently the best way to persist value objects with EF Core 2.0 and later. The owned entity type feature was added to EF Core since version 2.0.

How to use Entity Framework with a list of value objects?

Even if Entity Framework supports Enum, it is not strongly typed inside the database. The database does not have a foreign key so it could be possible to set a value that would not be in C#. Because of how Entity Framework works, we cannot simply have an entity to have a list of value objects.

When does an entity hold reference to a value object?

When an entity holds a reference to a Value Object, there is basically two choices: The Value Object can be serialized in a format such as JSON or XML to a column of the Entity table. The inability to execute queries referring to the contents of the Value Object can pose problem though.

Can a value object belong to more than one entity?

A guideline that flows from this distinction is that value objects cannot live by their own, they should always belong to one or several entities. The data a value object represents has a meaning only in the context of an entity it refers to. In the example above with people and money, the question “How much money?”