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POUpdating a entity using Entity Framework 4.3 - Code First
 

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  1. POUpdating a entity using Entity Framework 4.3 - Code First
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    <p>I'm having a hard time updating entities in Entity Framework.</p> <p>The scenario: - I load a entity with new DbContext().GetById(guid) - I try to save this entity using a extension method, then using a new DbContext()</p> <p>Heres my Update method:</p> <pre><code> public virtual void Update(IEntity entityToUpdate) { var dbEntry = Context.Entry(entityToUpdate); if (dbEntry == null) return; if (Context.Entry(entityToUpdate).State == EntityState.Detached) DbSet.Attach(entityToUpdate); else { dbEntry.CurrentValues.SetValues(entityToUpdate); Context.Entry(entityToUpdate).State = EntityState.Modified; } Context.SaveChanges(); } </code></pre> <p>This is a collection of attemps by me. If I use SetValues I'm told that the entity is detached and therefor not possible, and If I use the attach I get the following error: 'An object with the same key already exists in the ObjectStateManager. The ObjectStateManager cannot track multiple objects with the same key.'</p> <p>I'm obviously doing something fundamentally wrong. Can someone please help me in the right direction?</p> <p>UPDATE:</p> <pre><code> protected void TransferClubs(object sender, EventArgs e) { var clubHelper = new ClubHelper(); var club = clubHelper.GetClub(new Guid("A009D0CD-71C4-42E8-88E2-037F059B12EE")); club.AddUser(Guid.NewGuid(), ClubRoleType.Admin); club.AddUser(Guid.NewGuid(), ClubRoleType.Admin); club.Save(); } public static bool Save(this ClubItem item) { var clubHelper = new ClubHelper(); clubHelper.AddOrUpdate(item); return true; } public ClubItem AddOrUpdate(ClubItem item) { if (item.Id == Guid.Empty) Insert(item); else Update(item); return item; } </code></pre> <p>And the Update() method you see in my original post...</p>
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    1. USKulvis
    1. USKulvis
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    1. COCan you give an example of the full context between loading the entity, changing it and then calling this Update method? You say that Update happens with a "new DbContext()" but then you have an exception about already existing (=attached) objects with the same key. I can't imagine how this could happen in a *new* context.
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      1. POUpdating a entity using Entity Framework 4.3 - Code First
      1. USSlauma
    2. COAdded all the methods in play. The AddUser adds new Users to a ICollection<ClubUsers> collection
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      1. USKulvis
    3. CO`ClubHelper` creates a new context, `GetClub` loads an existing club from the DB and `AddUser` is supposed to create a new user, insert it into the DB and set a reference to the club, right?
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      1. USSlauma
 

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