object with same key already exists objectstatemanager

Question

I am having an entity which holds the virtual collection of another entity. When i try to insert the data by filling the virtual collection for the newly inserted objects it is throwing the error that object with same key already exists.

I know that when the entity is not created it will have identity field with 0 value. But i need to store the collection of data when i store the data in main table.

public virtual void Insert(TEntity entity)
    {
        ((IObjectState)entity).ObjectState = ObjectState.Added;
        entityDbSet.Attach(entity);
        dataContext.SyncObjectState(entity);
    }

This is the insert method that i am using. and below is the poco classes (partial implementation for extending the classes to hold the collection of data) for this operation.

public partial class UserDefinedData
{
    public int ID { get { return this.UserSelectedDValueID; } set { this.UserSelectedDValueID = value; } }
    public string Name { get { return this.entityTypeName; } }

    public virtual AM_AssetLocations AM_AssetLocations { get; set; }
}

public partial class AM_AssetLocations
{
    // Reverse navigation
    public virtual ICollection<UserDefinedData> UserDefinedDatas { get; set; }               
}

I am passing the data using json. Which is also seems correct. as the virtual collection of data is added to the entity correctly.

{"entity":{"ID":"0","CreatedByID":"0","CreatedDate":"04-13-2014 10:48","ModifiedByID":"","ModifiedDate":"","DeletedByID":"","DeletedDate":"","Deleted":"false","Name":"h","Active":"true","DisplayOrder":"0","Test Decimal":"10","":"","Test Number":"10","Test Plain Text":"h","Test RTF":"<p>hsj</p>","Test Yes No":"false","Test Yes No 2":"true","TestDate":"01-Apr-2014","TestDateTime":"10:00 AM","UserDefinedDatas":[{"EntityType":"AM_AssetLocations","EntityTypeID":"0","CreatedByID":"0","UserDefinedFieldID":"123","ValueNumber":"10"},{"EntityType":"AM_AssetLocations","EntityTypeID":"0","CreatedByID":"0","UserDefinedFieldID":"124","ValueListItemID":"25"},{"EntityType":"AM_AssetLocations","EntityTypeID":"0","CreatedByID":"0","UserDefinedFieldID":"122","ValueNumber":"10"},{"EntityType":"AM_AssetLocations","EntityTypeID":"0","CreatedByID":"0","UserDefinedFieldID":"117","ValueString":"h"},{"EntityType":"AM_AssetLocations","EntityTypeID":"0","CreatedByID":"0","UserDefinedFieldID":"119","ValueString":"<p>hsj</p>"},{"EntityType":"AM_AssetLocations","EntityTypeID":"0","CreatedByID":"0","UserDefinedFieldID":"125","ValueYesNo":0},{"EntityType":"AM_AssetLocations","EntityTypeID":"0","CreatedByID":"0","UserDefinedFieldID":"126","ValueYesNo":1},{"EntityType":"AM_AssetLocations","EntityTypeID":"0","CreatedByID":"0","UserDefinedFieldID":"120","ValueDate":"01-Apr-2014"},{"EntityType":"AM_AssetLocations","EntityTypeID":"0","CreatedByID":"0","UserDefinedFieldID":"121","ValueDate":"08-Apr-2014 10:00 AM"}]}}

Please help me to solve this issue.

Note : Just to solve this same key exception if i try to assign the identity field my self it is throwing referential integrity exception. I know that storing the realative collection should work fine. but it is not working for me. please give me some guidance and solution for this.

Thanks, sachin

Answer 1

Attach is for attaching existing entities.

Context should assign proper state itself, there's no need to do it manually in your case

public virtual void Insert(TEntity entity)
{
    //((IObjectState)entity).ObjectState = ObjectState.Added;
    context.TEntityDbSet.Add(entity);//Add, not Attach!
    //dataContext.SyncObjectState(entity);
    context.SaveChanges()
}

.. http://msdn.microsoft.com/en-us/data/jj592676.aspx

Answer 2

Hi Thanks all for helping out. I changed the way to perform this operation. I have created the stored procedure which accepts the main entity and user defined table type of child collection which can be passed as dataset from .net page. And this works fine for me.

thanks.