这是我的 3 个实体模型:Route、Location 和 LocationInRoute。

以下方法失败并在提交时出现异常:

 public static Route InsertRouteIfNotExists(Guid companyId, IListLocation> locations)
        {
            //Loop on locations and insert it without commit
            InsertLocations(companyId, routesOrLocations);

            RouteRepository routeRep = new RouteRepository();
            Route route = routeRep.FindRoute(companyId, locations);
            if (route == null)
            {
                route = new Route()
                {
                    CompanyId = companyId,
                    IsDeleted = false
                };
                routeRep.Insert(route);
                LocationInRouteRepository locInRouteRep = new LocationInRouteRepository();
                for (int i = 0; i < locations.Count; i++)
                {
                    locInRouteRep.Insert(new LocationInRoute()
                    {
                        //Id = i,
                        LocationId = locations[i].Id,
                        Order = i,
                        RouteId = route.Id
                    });
                }
            }
            return route;
        }

做的时候:

InsertRouteIfNotExists(companyId, locations);
UnitOfWork.Commit();

我得到了:

Unable to determine the principal end of the 'SimTaskModel.FK_T_STF_SUB_LOCATION_IN_ROUTE_T_STF_LOCATION_location_id' relationship. Multiple added entities may have the same primary key.

当拆分提交并插入到方法中时 - 它有效:

  public static Route InsertRouteIfNotExists(Guid companyId, IListLocation> locations)
            {
                //Loop on locations and insert it without commit
                InsertLocations(companyId, routesOrLocations);
                UnitOfWork.Commit();

                RouteRepository routeRep = new RouteRepository();
                Route route = routeRep.FindRoute(companyId, locations);
                if (route == null)
                {
                    route = new Route()
                    {
                        CompanyId = companyId,
                        IsDeleted = false
                    };
                    routeRep.Insert(route);
                    LocationInRouteRepository locInRouteRep = new LocationInRouteRepository();
                    for (int i = 0; i < locations.Count; i++)
                    {
                        locInRouteRep.Insert(new LocationInRoute()
                        {
                            //Id = i,
                            LocationId = locations[i].Id,
                            Order = i,
                            RouteId = route.Id
                        });
                    }
                    UnitOfWork.Commit();
                }
                return route;
            }

我想在方法之外调用一次提交。为什么它在第一个示例中失败，这个异常意味着什么？

最佳答案

错误是由无法解析的外键 ID(而不是引用)引起的。在您的例子中，您有一个引用 ID 为 0 的位置的 LocationInRole。有多个具有此 ID 的位置。

位置尚未分配 ID，因为它们尚未保存到生成 ID 时的数据库中。在您的第二个示例中，位置在访问其 ID 之前被保存，这就是它起作用的原因。

如果您以后只想保存更改，您将无法依赖位置 ID 来定义关系。

交换以下行...

LocationId = locations[i].Id

...为此...

Location = locations[i]

关系将基于不依赖于 LocationID 的对象引用。

关于c# - 多个添加的实体可能具有相同的主键，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/6041057/