Insert multiple records using Linq to Entities (EF)

Question

I have a map table (tblUserRoles) which can contain multiple records. When i insert only one record using L2E it saves but when try to save multiple records it gives exception. I am saving like this:

foreach (tblUserRoles u in InsertUserRole)
{   
     EntityHelperUtil.AddObject(context, "tblUserRoles", (IEntityWithRelationships)u);                            
}

context.SaveChanges();

I am using a utility class of EntityHelperUtil from(http://bernhardelbl.spaces.live.com/blog/cns!DB54AE2C5D84DB78!238.entry) Here is the exception:

AttachSingleObject(System.Object, System.Data.Metadata.Edm.EntitySet, System.String)---An object with the same key already exists in the ObjectStateManager. The ObjectStateManager cannot track multiple objects with the same key.
   at System.Data.Objects.ObjectContext.AttachSingleObject(Object entity, EntitySet entitySet, String argumentName)
   at System.Data.Objects.DataClasses.RelatedEnd.AddEntityToObjectStateManager(IEntityWithRelationships entity, Boolean doAttach)
   at System.Data.Objects.DataClasses.RelatedEnd.AddGraphToObjectStateManager(IEntityWithRelationships entity, Boolean relationshipAlreadyExists, Boolean addRelationshipAsUnchanged, Boolean doAttach, HashSet`1 promotedEntityKeyRefs)
   at System.Data.Objects.DataClasses.RelatedEnd.IncludeEntity[U](U entity, Boolean addRelationshipAsUnchanged, Boolean doAttach, HashSet`1 promotedEntityKeyRefs)
   at System.Data.Objects.DataClasses.EntityCollection`1.Include(Boolean addRelationshipAsUnchanged, Boolean doAttach, HashSet`1 promotedEntityKeyRefs)
   at System.Data.Objects.DataClasses.RelationshipManager.AddRelatedEntitiesToObjectStateManager(Boolean doAttach)
   at System.Data.Objects.ObjectContext.AttachTo(String entitySetName, Object entity)
   at System.Data.Objects.ObjectContext.Attach(IEntityWithKey entity)
   at HealthSphereServices.EntityHelperUtil.AddRelationships(ObjectContext context, List`1 map) in E:\E_Drive data\ORB\ORB_Development\ControlRoom\ControlRoom\HealthSphereServices\EntityHelperUtil.cs:line 158

Answer 1

Seems like you have either:

1. A duplicate, client-generated PK value, or
2. A server-generated PK which is not mapped as such in your EDMX. Hence, the EF doesn't ignore the PK values on the new object.

I can't say more without seeing your model.