We’ve created a CrmContact entity class which we will continue to use in this last part of the blog series. But so far, we’ve only operated on 1:N relationships between entities. This blog post will focus on how you can use the CRM Framework in order to operate on N:N relationships between entities.
N:N Relationships in MS CRM
You can view an entities N:N Relationships from ‘Settings’ –> ‘Customization’ –> ‘Customize Entities’ –> Entity –> ‘N:N Relationships’.
In the image above, you can see that the Contact entity has a N:N relationship with the Order entity. Now, how do we get all Orders associated with a Contact using this framework?
Creating entity classes
Let’s assume you already have a CrmContact entity class like the one created in part 1. For us to retrieve all Orders assiciated with a Contact entity, we also need to create a CrmOrder entity class:
public class CrmOrder
public Guid OrderId
public string Name
I haven’t included a lot of attributes in this class, as I only want to display the name of the Orders. You should make it a habit of always including the entity’s primary key attribute (in this case OrderId) to your entity classes! This is because you will always need to specify the primary key attribute when doing update operations on an entity. So now we have both the entity classes we need: CrmContact and CrmOrder.
Creating a CrmManyToManyRelationshipController
In the two previous blog posts we’ve used CrmEntityControllers in order to do operations on entities. When working with N:N Relationships we use a different controller: CrmManyToManyRelationshipController<T, V>, where T is the entity we have and V is the entity we want to be returned. In this example we have a Contact entity, and want to retrieve all Orders associated with the Contact, to T is the CrmContact class and V is the CrmOrder class:
CrmControllerFactory factory = CrmControllerFactory.Instance();
CrmManyToManyRelationshipController<CrmContact, CrmOrder> manyRelationshipController =
Of course, in order to create a CrmManyToManyRelationshipController, we need a CrmControllerFactory as shown in line 1 of the code above.
Using the Find method
Now that we have our controller, we can use the Find method in order to retrieve all CrmOrders associated with the CrmContact:
CrmManyToManyRelationshipController<T, V>.Find(CrmQuery query) : List<V>
CrmManyToManyRelationshipController<T, V>.Find(CrmQuery query, CrmSortingCriteria sorting) : List<V>
CrmManyToManyRelationshipController<T, V>.Find(CrmQuery query, int page, int pageSize, out int totalCount, CrmSortingCriteria sorting) : List<V>
Guid contactGuid = new Guid("50F16A2B-904B-DE11-8A4B-0003FFD726F0");
CrmQuery query = new CrmQuery();
query.AddCondition(new CrmAttributeCriterion("contactid", contactGuid, CrmConditionOperator.Equal));
List<CrmOrder> orders = manyRelationshipController.Find(query);
What happens in the example above is that we find all Orders of the Contact with contactid == contactGuid. As mentioned in the previos blog post, the CrmQuery class will change at some point. I’m not sure if I’ll change it before the release of the alpha version, but at some point I will definitely improve it!
I still need a couple of testers, so if you’d like to try the framework before it is released, let me know :)