Strange behaviror : duplicated entities when using sand box editors
Printed From: IdeaBlade
Category: DevForce
Forum Name: DevForce 2012
Forum Discription: For .NET 4.5
URL: http://www.ideablade.com/forum/forum_posts.asp?TID=4577
Printed Date: 06-Sep-2025 at 6:54am
Topic: Strange behaviror : duplicated entities when using sand box editors
Posted By: chk040399
Subject: Strange behaviror : duplicated entities when using sand box editors
Date Posted: 29-Oct-2013 at 1:32am
Hi !,
I have a strange behavior,
I 'm using sandbox editors to edit/add an entity,
I have a main entity manager, and an entity manager used to edit/add entities
When I create new entity, (using the sandbox EM), and import it to the main EM, there is no problem.
then I try to edit the newly created entity (which is not commited to Database) , in a new sandBox EM, and import it again
in the main EM, there is 2 new entities !!!
see the code below (I used linqpad, My model is named GeDoseEntities)
void Main()
{
var em1 = new GedoseEntities(); //main Entity Manager
// 1st editor
var em2 = new GedoseEntities(); //this EM will create the entity
var newsite = new Site() { Nom="service d", OrganismeId = 1};
em2.AddEntity(newsite);
//1st edition : creation
bool validateCreation = true;
if(validateCreation)
{
var entities = em2.FindEntities(IdeaBlade.EntityModel.EntityState.AnyAddedModifiedOrDeleted);
em1.ImportEntities(entities,MergeStrategy.OverwriteChanges);
}
else
{
em2.Clear();
return;
}
// at this point the newly crated entity is imported to the main EM , and there is only one instance
// dump into linqpad outut
em1.FindEntities(IdeaBlade.EntityModel.EntityState.AnyAddedModifiedOrDeleted).Dump("after creation");
// edit the newlyt created entity (!! : not commited to the database)
int id = newsite.Id;
var siteToEdit = em1.Sites.FirstOrDefault(s=>s.Id==id);
// EM used to edit the entity
var em3 = new GedoseEntities();
var entitiesToimport = em1.FindEntities(IdeaBlade.EntityModel.EntityState.AnyAddedModifiedOrDeleted);
em3.ImportEntities(entitiesToimport,MergeStrategy.OverwriteChanges);
em3.FindEntities(IdeaBlade.EntityModel.EntityState.AllButDetached).Dump("e3");
{
var siteToModify = em3.Sites.FirstOrDefault(s=>s.Id==id);
// modif
siteToModify.Nom += "+++";
siteToEdit.Dump("site to edit");
siteToModify.Dump("site to modify");
}
bool validateModification = true;
if(validateModification)
{
var entities = em3.FindEntities(IdeaBlade.EntityModel.EntityState.AnyAddedModifiedOrDeleted);
em1.ImportEntities(entities,MergeStrategy.OverwriteChanges);
}
else
{
em3.Clear();
}
em1.FindEntities(IdeaBlade.EntityModel.EntityState.AnyAddedModifiedOrDeleted).Dump("To update");
// at this point there is two new entities !!!
}
Thanks
|
Replies:
Posted By: kimj
Date Posted: 29-Oct-2013 at 9:59am
|
This strange behavior occurs because you're using temporary ids. While temporary ids can be useful they also have drawbacks, most specifically in that they don't provide a true fixed identity for an entity. When importing, DevForce doesn't know that the Site entities in the two EMs are truly the same, and creates a new Site entity. You can work around this behavior by assigning real ids in your code, such as Guids, rather than having the database assign a real id when the item is saved.
|
|