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种子一对一关系ASP.NET MVC

entity-framework-6 entity-framework asp.net-mvc asp.net c#

Sfmar · 技术社区 · 6 年前

我正在使用ASP.NETMVC5和EF6构建一个web应用程序。

我正在尝试将数据播种到一对一关系,定义如下:

public class Client 
{
  public int ClientId { get; set; }  
  [Required]
  public string Name { get; set; }

  public Address Address { get; set; }
}

public class Address 
{
  [ForeignKey("Client")]
  public int AddressId { get; set; }  
  [Required]
  public string StreetName { get; set; }

  public Client Client { get; set; }
}

其中Address是从属端。

/迁移/Configuration.cs 我添加了以下代码:

internal sealed class Configuration : DbMigrationsConfiguration<MR_TrackTrace.Models.ApplicationDbContext>
    {
        public Configuration()
        {
            AutomaticMigrationsEnabled = false;
        }

        protected override void Seed(MR_TrackTrace.Models.ApplicationDbContext context)
        {

            var clients = new List<Client>
            {
                new Client { Name = "John" },
                new Client { Name = "Mary" },
                new Client { Name = "Philip" }
            };

            clients.ForEach(s => context.Clients.AddOrUpdate(p => p.Name, s));

            context.SaveChanges();
            var addresses = new List<Address>
            {
                new Address { StreetName = "something", Client = clients.FirstOrDefault(s => s.Name == "John") },
                new Address { StreetName = "other", Client = clients.FirstOrDefault(s => s.Name == "Philip") },
                new Address { StreetName = "another", Client = clients.FirstOrDefault(s => s.Name == "Mary") }
            };

            addresses.ForEach(s => context.Addresses.AddOrUpdate(p => p.Name, s));
            context.SaveChanges();
        }
 }

但此列没有用预期的ID填充,而是用“0”填充。通过使用:

Client = clients.FirstOrDefault(s => s.Name == "John")

我希望上下文会自动设置此表的ClientId。

提前谢谢!

2 回复 | 直到 6 年前

Alex Grogan 6 年前

您不能添加如下地址:

var clients = new List<Client>
{
    new Client { Name = "John", Address = new Address() { StreetName = "Something" } },
    new Client { Name = "Mary", Address = new Address() { StreetName = "Other" }  },
    new Client { Name = "Philip", Address = new Address() { StreetName = "Another" }  }
};

当它保存更改时,它应该同时创建客户机和地址,并将它们链接在一起

Sfmar 6 年前

通过如下方式解决了我的问题:

 protected override void Seed(MR_TrackTrace.Models.ApplicationDbContext context)
        {

            var clients = new List<Client>
            {
                new Client { Name = "John" },
                new Client { Name = "Mary" },
                new Client { Name = "Philip" }
            };

            clients.ForEach(s => context.Clients.AddOrUpdate(p => p.Name, s));

            context.SaveChanges();
            var addresses = new List<Address>
            {
                new Address { StreetName = "something", ClientId = context.Clients.FirstOrDefault(s => s.Name == "John").ClientId },
                new Address { StreetName = "other", ClientId = context.Clients.FirstOrDefault(s => s.Name == "Philip").ClientId },
                new Address { StreetName = "another", ClientId = context.Clients.FirstOrDefault(s => s.Name == "Mary").ClientId }
            };

            addresses.ForEach(s => context.Addresses.AddOrUpdate(p => p.Name, s));
            context.SaveChanges();
        }

仍然不知道为什么EF不能链接这两个表并在Address表中自动填充ClientId。