CODEWITHSUNDEEP
wcfentity-framework
Gavin
Gavin

Reputation: 17382

Entity Framework and WCF (Returning Entities Attached To Context)

I have a WCF service that calls the following method in one of my Repository objects to create a new sale object in the database

public static Sale New(Sale sale)
{
    using (var ctx = new DBcontext())
    {
        ctx.Sales.AddObject(sale);
        ctx.SaveChanges();
        return sale;
    }
}

The WCF method calling this looks like this

public Sale SaleNew(Sale sale)
{
    return SaleRepository.New(sale);
}

When I call this from a client application I get the following error

"The underlying connection was closed: The connection was closed unexpectedly."

If I step through all the code seems to run fine and the record gets insterted into the database. If I add the following line to my repository method after the SaveChanges it works fine

ctx.Detach(sale);

Is the exception happening because I'm disposing the context as soon as the method returns? Is using the entity context in this way bad practise ie disposing of it straight away? I'm only doing this because its SOA and pretty much stateless so all my repository methods create the context return the value and dispose the context. Anything that is passed in will either get added to the context or re-attached.

Upvotes: 2

Views: 1669

Answers (2)

Gavin
Gavin

Reputation: 17382

As advised I turned on tracing in WCF and watched what was happening. There was a proxy exception occurring. In this case as I'm using my own POCO objects I don't really want proxy objects so I set the ContextOptions.ProxyCreationEnabled property in my DatabaseContext to false and it now works fine.

Upvotes: 3

Aliostad
Aliostad

Reputation: 81660

1) Is using the entity context in this way bad practise ie disposing of it straight away?

No, that's how I do it - and I believe it is the proper way of doing it. But creating context can be expensive and with EF we are stuck with no ideal way of reusing the context.

2) ctx.Detach(sale);

This as far as I know should not be required for what you are doing although I have had loads of issues with attaching and detaching when I reuse the same entities. This should be only needed if you need to re-attach to context. Are you using Lazy-Loading?

Upvotes: 2

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