CODEWITHSUNDEEP
entity-frameworkentity-framework-4
mare
mare

Reputation: 13083

Entity Framework v4 POCO templates: repository returns object of incorrect type

I've just implemented a repository based on EFv4 POCO entity templates.

When I do this

public Client Load(Guid firmId,
                   int prettyId)
{
    var client = (from c in _ctx.Clients where c.firm_id == firmId && c.PrettyId == prettyId select c).FirstOrDefault();
    return client;
}

the client returned is of type 

{System.Data.Entity.DynamicProxies.Client_8E92CA62619EB03F03DF1A1FC60C5B21F87ECC5D85B65759DB3A3949B8A606D3}

What is happening here? I thought I would get rid of any reference to types from System.Data.Entity namespace. The returned instance should be of type Client, which is a simple POCO class.

Upvotes: 2

Views: 2025

Answers (3)

Jenn
Jenn

Reputation: 902

This can be configured globally for the EF context in the *Model.Context.tt file in *Model.edmx under

if (!loader.IsLazyLoadingEnabled(container))

...

    this.Configuration.LazyLoadingEnabled = false;
    this.Configuration.ProxyCreationEnabled = false;

These will be added to the *Model.context.cs generated file, and will persist between updates from the Database.

I prefer this setting as I do not want a child object that matches the parent loaded from the database.

ALT: It can be configured for Json serizialization: JSON.NET Error Self referencing loop detected for type

Upvotes: 0

Andy Thomas
Andy Thomas

Reputation: 1367

I agree that Mare's answer is correct. However, I would add a note of caution. If you run a query without this ProxyCreationEnabled setting set to true, then EF will return DynamicProxies. If you subsequently run a query with the setting set to false, then EF will return the cached DynamicProxies objects, regardless of the ProxyCreationEnabled setting.

Upvotes: 0

mare
mare

Reputation: 13083

I can confirm that the solution is to set 

context.ProxyCreationEnabled = false;

which disables creation of dynamic proxy typed objects and leaves us with simple POCOs, which is what we were after with EF POCO templates in the first place.

But you lose lazy loading of navigation properties and change tracking on entities. For the first, you either have to use context.LoadProperty() or the Include() method on your ObjectQuery object. For the second, I do not know the solution yet (actually it doesn't really make sense to have change tracking on POCOs).

Also here is a similar question I would like to point out What are the downsides to turning off ProxyCreationEnabled for CTP5 of EF code first

Upvotes: 2

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