使用 Linq to Entities (EF) 插入多条记录

Question

我有一个映射表（tblUserRoles），它可以包含多个记录。当我使用 L2E 仅插入一条记录时，它会保存，但当尝试保存多条记录时，它会出现异常。我像这样保存：

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

context.SaveChanges();

我正在使用来自(的EntityHelperUtil实用程序类http://bernhardelbl.spaces.live.com/blog/cns!DB54AE2C5D84DB78!238.entry) 这是例外情况：

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

似乎您有：

1. 重复的客户端生成的 PK 值，或
2. 服务器生成的 PK，但未在您的 EDMX 中进行映射。因此，EF 不会忽略新对象上的 PK 值。

在没有看到你的模型之前我不能说更多。