EF4 Code First CTP5：种子方法不再有效

我有EF Code First CTP4工作正常，我今天安装了CTP5。 现在，我重新填充数据库时出现exception。

这是我的模型：

public class Member { public Member() { DateCreated = DateTime.Now; DateUpdated = DateTime.Now; DateLastLogin = DateTime.Now; } [Key, DatabaseGenerated(DatabaseGenerationOption.Identity)] \\I have tried removing these annotations and the result is the same public int MemberId { get; set; } [Required,RegularExpression(".+\\@.+\\..+", ErrorMessage = "Please enter a valid email address")] public string Email { get; set; } [Required,StringLength(20,MinimumLength=2)] public string FirstName { get; set; } [Required, StringLength(20, MinimumLength = 2)] public string LastName { get; set; } [Required, StringLength(36, MinimumLength = 2)] public string City { get; set; } [Required, StringLength(20, MinimumLength = 2)] public string State { get; set; } [Required, StringLength(20, MinimumLength = 2)] public string Zip { get; set; } public double GeoLat { get; set; } public double GeoLong { get; set; } public string AccountStatus { get; set; } public DateTime DateCreated { get; private set; } public DateTime DateUpdated { get; set; } public DateTime DateLastLogin { get; set; } public virtual PublicProfile Profile { get; set; } } 

这是在Global.asax.cs中调用的代码

 protected void Application_Start() { RegisterRoutes(RouteTable.Routes); DbDatabase.DefaultConnectionFactory = new SqlConnectionFactory("System.Data.SqlClient"); DbDatabase.SetInitializer(new Initializer()); } public class Initializer : DropCreateDatabaseAlways { protected override void Seed(MeetPplDB context) { var Members = new List { new Member { Email = "[e-mail]", City = "San Francisco", AccountStatus = "Active", State = "CA", FirstName = "David", LastName = "Daverson", Zip = "94118", GeoLat = 37.735, GeoLong = -122.392 }, new Member { Email = "[e-mail]", City = "Oakland", AccountStatus = "Active", State = "CA", FirstName = "Bob", LastName = "Boberson", Zip = "94601", GeoLat = 37.781, GeoLong = -122.216 }, new Member { Email = "[e-mail]", City = "San Francisco", AccountStatus = "Active", State = "CA", FirstName = "Jenny", LastName = "Jennerson", Zip = "94123", GeoLat = 37.735, GeoLong = -122.392 } }; Members.ForEach(m => context.Members.Add(m)); context.SaveChanges(); } } 

当它在上下文中遇到SaveChanges时，我得到以下exception：

检测到冲突的更改。 尝试使用相同的密钥插入多个实体时可能会发生这种情况。

描述：执行当前Web请求期间发生未处理的exception。 请查看堆栈跟踪以获取有关错误及其源自代码的位置的更多信息。

exception详细信息：System.Data.UpdateException：检测到冲突的更改。 尝试使用相同的密钥插入多个实体时可能会发生这种情况。

有没有人知道发生了什么变化以及为什么这不再起作用了？ 需要改变什么才能发挥作用？

Answer 1

也许是因为您使用的变量名已被EF生成为多元化。

代替 ：

 public class Initializer : DropCreateDatabaseAlways { protected override void Seed(MeetPplDB context) { var Members = new List { new Member { Email = "[e-mail]", City = "San Francisco", ..... 

试试这个

 public class Initializer : DropCreateDatabaseAlways { protected override void Seed(MeetPplDB context) { var _members = new List { new Member { Email = "[e-mail]", City = "San Francisco", .... _members.ForEach(m => context.Members.Add(m)); context.SaveChanges(); 

我将您的代码与Scott Gu的http://weblogs.asp.net/scottgu/archive/2010/07/16/code-first-development-with-entity-framework-4.aspx进行比较

Answer 2

您的exception的原因是您将数据类型int与DatabaseGenerationOption.Identity结合使用。 使用identity将生成guid而不是int键。

我有一个类似的问题，因为我想要一个类型为int的键和一个Guid作为唯一的rowid。 如果我在一个实体上使用它们，即使它们在不同的道具中，种子也会停止工作。