MVC5引用的Guid

Question

我創建一個表像這樣：

public class Team 
{ 
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
    public Guid Id { get; set; } 
    public string CaptainId { get; set; } 
    public string CoCaptainId { get; set; } 
    public string ContactDetails { get; set; } 
} 

然後，我有一個表像這樣：

public class TeamMember 
{ 
    public string Id { get; set; } 
    public string Description { get; set; } 
    public string GameDisplayName { get; set; } 
    public DateTime Joined { get; set; } 
    public string TeamId { get; set; } 
} 

我有2個問題，我不周圍EF 6理解和MVC5。

1）如何在Team表中引用我的Id字段。我是否將TeamId作爲字符串或Guid設置在TeamMember中？我知道我需要設置屬性[ForeignKey("Team")]，但我仍然不明白如何在代碼中正確引用它，因爲無論何時需要進行任何類型的比較，我都必須在Guid上輸入.ToString()才能夠獲得與另一個字符串值進行比較的值。

2）我的TeamMember也有一個Id，並且此Id在Identity框架中引用用戶。我應該如何引用那個，Id是爲了引用用戶表中的Id的外鍵，但我不知道如何正確地引用那個，它是像我這樣做的字符串，還是Guid或某個東西其他？

編輯：

public class Team 
{ 
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
    public Guid Id { get; set; } 
    public Guid CaptainId { get; set; } 
    public Guid CoCaptainId { get; set; } 
} 

public class TeamMember 
{ 
    public Guid MemberId { get; set; } 
    public string TeamId { get; set; } 
    public virtual Team Team { get; set; } 
    public virtual Member Member { get; set; } 
} 

public class Member : IdentityUser 
{ 
    public string FirstName { get; set; } 
    public string LastName { get; set; } 
    public string About { get; set; } 
    public string Alias { get; set; } 
    public string CustomUrl { get; set; } 

    public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<Member> manager) 
    { 
     // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType 
     var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie); 
     // Add custom user claims here 
     return userIdentity; 
    } 
} 

public class ApplicationDbContext : IdentityDbContext<Member> 
{ 
    public ApplicationDbContext() 
     : base("DefaultConnection") 
    { 
    } 

    public DbSet<Team> Teams { get; set; } 
    public DbSet<TeamMember> TeamMembers { get; set; } 

    protected override void OnModelCreating(DbModelBuilder modelBuilder) 
    { 
     base.OnModelCreating(modelBuilder); 
     modelBuilder.Entity<IdentityUserClaim>().ToTable("MemberClaim"); 
     modelBuilder.Entity<IdentityUserRole>().ToTable("MemberRole"); 
     modelBuilder.Entity<IdentityUserLogin>().ToTable("MemberLogin"); 
     modelBuilder.Entity<IdentityRole>().ToTable("Role"); 
     modelBuilder.Entity<Member>().ToTable("Member"); 
     modelBuilder.Conventions.Remove<PluralizingTableNameConvention>(); 
     modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>(); 
    } 

    public static ApplicationDbContext Create() 
    { 
     return new ApplicationDbContext(); 
    } 
} 

錯誤，我得到：

var user = new Member { UserName = model.Email, Email = model.Email, CustomUrl = model.CustomUrl, Alias = model.Alias}; 
var team = new Team {CaptainId = user.Id, Created = currentTime, IsSingleMember = true}; 

CaptainId = user.Id gives an error:

Cannot convert source type 'string' to target type 'System.Guid'

Answer 1

你應該使用相同的類型，這是Guid。

public Guid TeamId { get; set; } 

此外，你需要保持Team類型的virtual Team財產在你TeamMember模型。通常還有int或long或Guid是用於表的主鍵的類型。 string可能不是一個好主意，因爲您需要執行自定義代碼來生成表中不存在的字符串。

這將生成具有適當外鍵關係的2個表。

public class Team 
{ 
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
    public Guid Id { get; set; } 
    public string CaptainId { get; set; } 
    public string CoCaptainId { get; set; } 
    public string ContactDetails { get; set; } 
} 
public class TeamMember 
{ 
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
    public Guid Id { get; set; } 
    public string Description { get; set; } 
    public string GameDisplayName { get; set; } 
    public DateTime Joined { get; set; } 
    public Guid TeamId { get; set; } 
    public virtual Team Team { set; get; } 
} 

您現在不需要做ToString()轉換以進行比較。你可以這樣做YourGuid1==YourGuid2表達式