在三个表上使用GraphDiff

Question

我有三张桌子

ShippingZone
    ShippingZoneID -> PK

ZoneShippingMethod:
    ZoneShippingMethodID -> PK
    ShippingZoneID -> FK

ZoneShippingMethodRange
    ZoneShippingMethodID -> FK

背景：

public ShippingZonesContext()
            : base("name=ShippingZonesContext")
        {
        }

        public virtual DbSet<ShippingZone> ShippingZones { get; set; }
        public virtual DbSet<ZoneShippingMethod> ZoneShippingMethods { get; set; }
        public virtual DbSet<ZoneShippingMethodRange> ZoneShippingMethodRanges { get; set; }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.Entity<ShippingZone>()
                .Property(e => e.ZoneCountryIDs)
                .IsUnicode(false);

            modelBuilder.Entity<ShippingZone>()
                .Property(e => e.ZoneStateIDs)
                .IsUnicode(false);

            modelBuilder.Entity<ShippingZone>()
                .HasMany(e => e.ZoneShippingMethods)
                .WithRequired(e => e.ShippingZone)
                .WillCascadeOnDelete(false);

            modelBuilder.Entity<ZoneShippingMethod>()
                .Property(e => e.UserID)
                .IsUnicode(false);

            modelBuilder.Entity<ZoneShippingMethod>()
                .Property(e => e.Password)
                .IsUnicode(false);

            modelBuilder.Entity<ZoneShippingMethod>()
                .Property(e => e.ShippingServiceTypeIDs)
                .IsUnicode(false);

            modelBuilder.Entity<ZoneShippingMethod>()
                .Property(e => e.AccessKey)
                .IsUnicode(false);

            modelBuilder.Entity<ZoneShippingMethod>()
                .Property(e => e.ShipperNumber)
                .IsUnicode(false);

            modelBuilder.Entity<ZoneShippingMethod>()
                .HasMany(e => e.ZoneShippingMethodRanges)
                .WithRequired(e => e.ZoneShippingMethod)
                .WillCascadeOnDelete(false);
        }

当前代码：

context.UpdateGraph(shippingZone, map => map
                        .OwnedCollection(p => p.ZoneShippingMethods).OwnedCollection(p => p.ZoneShippingMethods.FirstOrDefault().ZoneShippingMethodRanges)
                    );

给出此错误：

不支持更新映射中使用的方法。

有什么线索吗？

谢谢和问候。

Answer 1

您的映射使用的是在FirstOrDefault映射中不支持的GraphDiff，因此这会产生错误。

在您的例子中，正确的映射如下：

context.UpdateGraph(shippingZone, 
    map => map.OwnedCollection(zone => zone.ZoneShippingMethods, 
        with => with.OwnedCollection(method => method.ZoneShippingMethodRanges)));