EF Core 一对一关系简单配置

一对一（注意：必须显示的在其中一个实体类中声明一个外键属性，并配置外键（HasForeignKey））

1、创建实体类

 class Order
{
    public long Id { get; set; }
    public string Name { get; set; }
    public string Address { get; set; }
    public Delivery Delivery { get; set; }
}

 class Delivery
{
    public long Id { get; set; }
    public string CompanyName { get; set; }
    public string Number {  get; set; } 
    public Order Order { get; set; }

    //显示声明外键属性
    public long OrderId {  get; set; }
}

2、创建配置文件，并配置外键
OrderConfig

class OrderConfig : IEntityTypeConfiguration<Order>
{
    public void Configure(EntityTypeBuilder<Order> builder)
    {
        builder.ToTable("T_Orders");
        builder.HasOne<Delivery>(a => a.Delivery).WithOne(o => o.Order)
            .HasForeignKey<Delivery>(c => c.OrderId);

    }
}

DeliveryConfig

class DeliveryConfig : IEntityTypeConfiguration<Delivery>
{
    public void Configure(EntityTypeBuilder<Delivery> builder)
    {
        builder.ToTable("T_Deliverys");
    }
}

3、创建MyDbContext

 class MyDbContext:DbContext
{
    public DbSet<Order>  Orders { get; set; }
    public DbSet<Delivery> Deliverys { get; set; }
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        base.OnConfiguring(optionsBuilder);
        optionsBuilder.UseSqlServer("Server=DESKTOP-7K7ADF7;Database=EFCore5;User Id=sa;Password=XXX;TrustServerCertificate=True;Trusted_Connection=True;MultipleActiveResultSets=True;");
            .EnableSensitiveDataLogging() // 显示敏感数据（仅用于调试）
            .LogTo(Console.WriteLine, LogLevel.Debug);
    }
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.ApplyConfigurationsFromAssembly(this.GetType().Assembly);       
    }
}

4、插入数据

using (MyDbContext dbContext = new MyDbContext())
{
    Order order=new Order();
    order.Name= "订单2";
    order.Address = "深圳福田";
    Delivery dly = new Delivery();
    dly.CompanyName = "申通";
    dly.Number = "ST001001002";
    dly.Order=order;
    order.Delivery = dly;
    
    dbContext.Orders.Add(order);
    await dbContext.SaveChangesAsync();
}