CODEWITHSUNDEEP
entity-framework
JohnathanKong
JohnathanKong

Reputation: 1307

Change Entity State

I currently have an entity model with a bunch of deleted items, the state is deleted. Is there a way to "undelete" them? I know which Items I want to undelete, but I don't know how to undelete the items. Ideally I'd like to get it back to an unchanged state.

Upvotes: 4

Views: 11036

Answers (3)

Iman Shabanzade
Iman Shabanzade

Reputation: 1

you can implement RejectChanges method for your Context, ObjectSet or EntityObject. Now I write VB Code of these methods: Extension method for RejectChanges in Context:

<Extension()>
Sub RejectChanges(ByVal Context As ObjectContext)
    Dim Collectin As IEnumerable(Of Object) = From e In Context.ObjectStateManager.GetObjectStateEntries(System.Data.EntityState.Modified Or System.Data.EntityState.Deleted) Select e.Entity
    Context.Refresh(RefreshMode.StoreWins, Collectin)

    Dim AddedCollection As IEnumerable(Of Object) = From e In Context.ObjectStateManager.GetObjectStateEntries(System.Data.EntityState.Added) Select e.Entity
    For Each addedEntity As Object In AddedCollection
        Context.Detach(addedEntity)
    Next
End Sub

Extension mehod for implementing RejectChanges in ObjectSet:

<Extension()>
Sub RejectChanges(Of T As MyEntity)(ByVal Lst As ObjectSet(Of T))
    Dim collection As IEnumerable(Of T) = From o In Lst.AsEnumerable() Where o.EntityState = EntityState.Modified Or o.EntityState = EntityState.Deleted Select o
    Lst.Context.Refresh(RefreshMode.StoreWins, collection)

    Dim AddedCollection As IEnumerable(Of T) = (From e In Lst.Context.ObjectStateManager.GetObjectStateEntries(System.Data.EntityState.Added) Select e.Entity).ToList().OfType(Of T)()
    For Each entity As T In AddedCollection
        Lst.Context.Detach(entity)
    Next
End Sub

and finally implementing RejectChanges for EntityObject:

<Extension()>
Sub RejectChanges(ByVal entity As EntityObject, ByVal Context As ObjectContext)
    If entity.EntityState = EntityState.Modified OrElse entity.EntityState = EntityState.Deleted Then
        Context.Refresh(RefreshMode.StoreWins, entity)
    ElseIf entity.EntityState = EntityState.Added Then
        Context.Detach(entity)
    End If
End Sub

bye. [Iman Shabanzade]

Upvotes: 0

Tion
Tion

Reputation: 1490

Do you have the option of just not committing the connection context? - dispose the ObjectContext without calling objectContext.SaveChanges(); Of course, if you have certain changes that you do wan't saved, they will not persist either.

If you called objectContext.DeleteObject(x) you can't undelete it and still save changes.

ObjectStateEntry objectStateEntry = objectContext.ObjectStateManager.GetObjectStateEntry(x);

// objectStateEntry.State is not setable

ObjectStateEntry does have the OriginalValues property so you could, in theory, painstakingly recreate a collection that represents the original changes, minus the unwanted ones, exit the objectContext, open a new one and rebuild those changes minus the unwanted ones there. Probably not worth the hassle, but there is no documented way to unmark something for deletion at this time.

Upvotes: 2

rale
rale

Reputation: 81

after you call

objectContext.DeleteObject(x),

you can simulate undelete of object x with

objectContext.Detach(x); objectContext.Attach(x)

Upvotes: 8

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