An entity object cannot be referenced by multiple instances of IEntityChangeTracker (again)

Question

I checked other questions and I am using the same DbContext for multiple actions so this is not the problem.

I have an MVC controller. Inside this controller I am doing the following:

var invites = await (from i in _db.Invitations
                     where i.User.Id == user.Id && i.Flat.Id == flat.Id
                     select i).ToListAsync();
_db.Invitations.RemoveRange(invites); //Error here
await _db.SaveChangesAsync();

Can someone explain to me why the error occurs?

Thanks a lot!

Edit: Thanks for your answers, i will try this. Currently I am instantiating my DbContext like this for each controller in my application.

private readonly ApplicationDbContext _db = new ApplicationDbContext();

Actually I don't like using a singleton for the DbContext. It should be possible to have another way. Maybe I will try to disable ChangeTracking or use usings for each and every action.

Thanks a lot. I will let you know tomorrow which solution I chose.

Hmm, I am receiving the error although I have

using(var db = new ApplicationDbContext){
    ...
}

around it ... any ideas?

try with static dbcontext, this error occurs when entity is attached to multiple context. It should work with static. if you don't like static then make sure you dispose the dbcontext after using it and before instantiating another dbcontext which try to attach same entity. or instantiate it in using block within controller. — Rajnikant, May 31 '14 at 15:47
Is there any existing code between the stuff that you posted that you have snipped out? — DavidG, May 31 '14 at 15:51

score 0 · Accepted Answer · edited May 23 '17 at 10:26

0

I don't know why, but it seems, that there really are references by other ApplicationDbContexts. Since I don't like the (complete) static approach, I am now creating an ApplicationDbContext per Request as posted here: https://stackoverflow.com/a/10153406/1636718

Thanks for your help!

edited May 23 '17 at 10:26

Community

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answered Jun 05 '14 at 15:43

david

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An entity object cannot be referenced by multiple instances of IEntityChangeTracker (again)

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