ASP.NET-Identity OnModelCreating Modelbuilder 生成重复的外键答案

【问题标题】：ASP.NET-Identity OnModelCreating Modelbuilder Generating Duplicate Foreign KeysASP.NET-Identity OnModelCreating Modelbuilder 生成重复的外键
【发布时间】：2016-07-13 11:17:38
【问题描述】：

我有一个 ASP MVC 5 应用程序，但模型构建器正在为 IdentityUserRole、IdentityUserClaim 和 IdentityUserLogin 表创建重复的外键。

例如，在下面生成的迁移表中，有 RoleId 和 IdentityRole_ID

CreateTable(
            "dbo.UserRole",
            c => new
                {
                    RoleId = c.String(nullable: false, maxLength: 128),
                    UserId = c.String(nullable: false, maxLength: 128),
                    IdentityRole_Id = c.String(maxLength: 128),
                    ApplicationUser_Id = c.String(maxLength: 128),
                })
            .PrimaryKey(t => new { t.RoleId, t.UserId })
            .ForeignKey("dbo.Role", t => t.IdentityRole_Id)
            .ForeignKey("dbo.User", t => t.ApplicationUser_Id)
            .Index(t => t.IdentityRole_Id)
            .Index(t => t.ApplicationUser_Id);

在我的 fluent api 中，我将其定义如下：

   public IdentityUserRoleConfiguration()
    {
        HasKey(x => new { x.RoleId, x.UserId });
        ToTable("UserRole");
    }

我的模型构建器类：

 public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
    // Add some DBSets      

    public ApplicationDbContext()
        : base("ApplicationDbContext", throwIfV1Schema: false)
    {
    }

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

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();

        // base.OnModelCreating(modelBuilder);

        modelBuilder.Configurations.Add(new IdentityUserRoleConfiguration());
        modelBuilder.Configurations.Add(new IdentityUserLoginConfiguration());
        modelBuilder.Configurations.Add(new IdentityRoleConfiguration());
        modelBuilder.Configurations.Add(new IdentityUserClaimConfiguration());
        modelBuilder.Configurations.Add(new ApplicationUserConfiguration());


    }

}

我已注释掉 base.OnModelCreating(modelBuilder); 语句，因为它在我运行迁移时会引发以下错误：

A configuration for type 'Microsoft.AspNet.Identity.EntityFramework.IdentityUserRole' has already been added. To reference the existing configuration use the Entity<T>() or ComplexType<T>() methods.

【问题讨论】：

标签： asp.net-mvc entity-framework asp.net-identity ef-fluent-api

【解决方案1】：

配置可以实现如下，

protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        modelBuilder.Entity<IdentityRole>().ToTable("Roles");
        modelBuilder.Entity<IdentityUserRole>().ToTable("UserRoles");
        modelBuilder.Entity<IdentityUserClaim>().ToTable("UserClaims");
        modelBuilder.Entity<IdentityUserLogin>().ToTable("UserLoginProviders");
        modelBuilder.Configurations.Add(new UserConfiguration());
    }

由于Microsoft.AspNet.Identity.EntityFramework中的大多数IdentityRole、IdentityUserRole、IdentityUserClaim、IdentityUserLogin模型已经实现了流畅的配置，因此它只允许覆盖ApplicationUser。因此，实现他的唯一方法是Entity<T>()

【讨论】：