Entity Framework 4 Navigation properties missing from Data Sources

Question

I have DB that contains 3 tables - Actors, Films, Actors_Films. 2 of the tables have a many-to-many relationship (Actors and Films), which is modelled using a junction table (Actors_Films).

I'm using EF4 in a Silverlight app. I've created a EF model, and the edmx designer shows just my Ac tors and Films entities, but they each have a navigation property to the other entity (Actors has a navigation property of Films, and Films has a navigation property of Actors).

I've added a domain service, and built the project. Using Actors as an example I now want to add a view that contains a dataform that will let me cycle through Actors, and a datagrid that will show any films the currently selected actor has appeared in. However, in the Data source tab, I have a domain context containing 2 entities - Actors and Films. These 2 entities are only showing their actual columns, the navigation properties aren't appearing:

Actors ---ActorID ---ActorName

Films ---FilmID ---FilmTitle

Is this correct? I thought the navigation properties should show up.

My actual application is more complicated than this, but this is a simplified example just to focus on the actual issue.

Thanks

Mick

MaxWave MaxWave · Accepted Answer · 2011-06-09T09:07:58

WCF Ria Services don't support Many To Many Relation. You must have association table on edmx. In order that Navigate properties appear on client you must add [Include] attribute to navigate property in apropriate metadata of Entity. The metadata usually generated when you create any DomainService. For example, we have relation many to many ContractPosition and OrderPosition:

//ContractPositionsService.metadata.cs
[MetadataTypeAttribute(typeof(ContractPosition.ContractPositionMetadata))]
public partial class ContractPosition
{
    internal sealed class ContractPositionMetadata
    {
        public int ContractPositionId { get; set; }
        [Include]
        public EntityCollection<ContractToOrderLink> ContractToOrderLinks { get; set; }

        ...
    }
//ContractToOrdersLinksService.metadata.cs
[MetadataTypeAttribute(typeof(ContractToOrderLink.ContractToOrderLinkMetadata))]
public partial class ContractToOrderLink
{

    internal sealed class ContractToOrderLinkMetadata
    {
        [Include]
        public ContractPosition ContractPosition { get; set; }

        public int ContractPositionId { get; set; }

        [Include]
        public OrderPosition OrderPosition { get; set; }

        public int OrderPositionId { get; set; }            
    }
}


//OrderPositionsService.metadata.cs
[MetadataTypeAttribute(typeof(OrderPosition.OrderPositionMetadata))]
public partial class OrderPosition
{               
    internal sealed class OrderPositionMetadata
    {
        public int OrderPositionId { get; set; }        

        [Include]
        public EntityCollection<ContractToOrderLink> ContractToOrderLinks { get; set; }

        ...
    }
}

Entity Framework 4 Navigation properties missing from Data Sources

1 Answers