五，表拆分与固有实体类型

表拆分与固有实体类型

表拆分 EF Core 中支持将两个或多个实体映射到单个表。 这称为表拆分或表共享。

public class Order { public int Id { get; set; } public OrderStatus Status { get; set; } public DetailedOrder DetailedOrder { get; set; } } public class DetailedOrder : Order { public string BillingAddress { get; set; } public string ShippingAddress { get; set; } } modelBuilder.Entity<DetailedOrder>() .ToTable("Orders") .HasBaseType((string)null) .Ignore(o => o.DetailedOrder); modelBuilder.Entity<Order>() .ToTable("Orders") .HasOne(o => o.DetailedOrder).WithOne() .HasForeignKey<Order>(o => o.Id);

固有的实体类型 显式配置

[Owned] public class StreetAddress { public string Street { get; set; } public string City { get; set; } } public class Order { public int Id { get; set; } public StreetAddress ShippingAddress { get; set; } } modelBuilder.Entity<Order>().OwnsOne(p => p.ShippingAddress);

当 ShippingAddress 为私有属性时可通过字符串版本的重载函数指定。

modelBuilder.Entity<Order>().OwnsOne(typeof(StreetAddress), "ShippingAddress");

默认情况下固有属性名为：Navigation_OwnedEntityProperty

modelBuilder.Entity<Order>().OwnsOne( o => o.ShippingAddress, sa => { sa.Property(p => p.Street).HasColumnName("ShipsToStreet"); sa.Property(p => p.City).HasColumnName("ShipsToCity"); });

多个相同类型的固有属性

public class OrderDetails { public DetailedOrder Order { get; set; } public StreetAddress BillingAddress { get; set; } public StreetAddress ShippingAddress { get; set; } }

嵌套固有的类型

public class StreetAddress { public string Street { get; set; } public string City { get; set; } } public class OrderDetails { public StreetAddress BillingAddress { get; set; } public StreetAddress ShippingAddress { get; set; } } public class Order { public int Id { get; set; } public OrderDetails OrderDetails { get; set; } } modelBuilder.Entity<Order>().OwnsOne(p => p.OrderDetails, od => { od.OwnsOne(c => c.BillingAddress); od.OwnsOne(c => c.ShippingAddress); });

将固有类型映射到单独表中

modelBuilder.Entity<DetailedOrder>().OwnsOne(p => p.OrderDetails, od => { od.OwnsOne(c => c.BillingAddress); od.OwnsOne(c => c.ShippingAddress); od.ToTable("OrderDetails"); });

固有类型的集合

modelBuilder.Entity<Distributor>().OwnsMany(p => p.ShippingCenters, a => { a.HasForeignKey("DistributorId"); a.Property<int>("Id"); a.HasKey("DistributorId", "Id"); });

查询固有的类型

var order = context.DetailedOrders.First(o => o.Status == OrderStatus.Pending);