These properties contain references to other objects. The UI allows the property to accept another object, but only if the property accepts the object type.

Declaring the type of relationship is important at this stage, as it describes lifetimes between objects. This is especially important when designing Aggregate Roots.

Consider two objects, A and B. The relationship type may be defined as:

In code, these relationships are declared using the Relationship attribute, like so:

[Relationship(RelationshipType.Has)] //👈
public Product Product { get; set; }

The Relationship Type drives how you interact with properties:

Only new objects can be assigned to the property (objects can only have one owner, and the property's parent is the owner). In the UI, use the Create option on the property:

Only existing objects can be assigned to the property (as those objects are typically owned by another parent). In the UI, use the Link with option on the property:

The UI only allows a selection from an existing set of objects, so you need to declare the query that will provide that set. See the Queries and Filters section for more information.

This property cannot be set by the UI. Typically this property is set within code, and merely displayed in the UI for navigation purposes:

• When adding a reference to an Aggregate Root, you may need an intermediary Aggregate Reference. See the Aggregate References section for more information.