The instance is transient

[Erik]

Sometimes, but not always, when I do a dbContext.SaveChanges, I get an InvalidOperationException: "The instance is transient"
Can someone explain to me what I am doing wrong?

[Ady]

Hello Erik,

 The exception is thrown when attempting to delete an object (context.Delete) that was has no context associated with it - maybe it was never added to the context ?
Can you review the code for types for which you get this exception?

All the best,
Ady
the Telerik team

[Erik]

Thanks Ady, your reply put me on the right track, in a 2nd save operation I was deleting the same object a second time, doh!

[Miladin]

Hi everybody,

Maybe this is not the right place to ask this question, but I spent last hour (or more) trying to find answer on this (Telerik ORM) forum with no success and this thread is closest to my needs :) so here it is:
Is there any property and/or function which can tell me if object is 'transient'?

As far as I am concerned I resolved this in not so beautiful way with try-catch

try
{
    Model.Delete(someEntity);
}
catch (InvalidOperationException ex)
{
    if (!ex.Message.Contains("transient"))
        throw ex;
}

From code above U can see that I had problems with deleting 'transient' objects and I would like to remove that ugly :) try-catch from my code and make it more desirable :)

Cheers

[Dimitar Tachev]

Hi Miladin,

In general you could avoid getting this exception by checking the object state.

The corresponding state for a transient object is the MaskNoMask one - an object becomes in this state when it is not managed by a context.

The following code snipped is demonstrating this approach.

ObjectState objectState = Model.GetState(someEntity);
if (objectState != ObjectState.MaskNoMask)
{
    Model.Delete(someEntity);
}

I hope this helps. Do not hesitate to contact us back if you need any further assistance.

Kind regards,
Dimitar Tachev
the Telerik team

[Miladin]

Thanks for quick reply.

One more thing - I think (and people will probably agree with me on this) that U should probably find a way to put stuff like this in docs, cause thats the 1st place were I've tried to find it :)

Cheers

[Dimitar Tachev]

Hi Miladin,

 
Thank you for your feedback.

The object states were not clearly described in our current resources but I already addressed this issue and you could find them updated in a future version of our online documentation.

All the best,
Dimitar Tachev
the Telerik team