asp.net-mvc – 数据库中已经有一个名为“AspNetRoles”的对象

Add-Migration InitialMigrations -IgnoreChanges

这应该会生成一个空白的“InitialMigration”文件.现在,添加任何所需的更改到你想要的类.添加更改后,再次运行update命令：

update-database -verbose

现在将应用自动迁移,并且您的更改将更改表.

编辑：
以下是将身份1迁移到2 Upgrading from ASP.NET.Identity 1.0 to 2.0的解决方案
使用此手动迁移

public override void Up()
    {
        RenameColumn(table: "dbo.AspNetUserClaims",name: "User_Id",newName: "UserId");
        RenameIndex(table: "dbo.AspNetUserClaims",name: "IX_User_Id",newName: "IX_UserId");
        DropPrimaryKey("dbo.AspNetUserLogins");
        AddColumn("dbo.AspNetUsers","Email",c => c.String(maxLength: 256));
        AddColumn("dbo.AspNetUsers","EmailConfirmed",c => c.Boolean(nullable: false));
        AddColumn("dbo.AspNetUsers","PhoneNumber",c => c.String()); 
        AddColumn("dbo.AspNetUsers","PhoneNumberConfirmed","TwoFactorEnabled","LockoutEndDateUtc",c => c.DateTime());
        AddColumn("dbo.AspNetUsers","LockoutEnabled","AccessFailedCount",c => c.Int(nullable: false));
        AlterColumn("dbo.AspNetUsers","UserName",c => c.String(nullable: false,maxLength: 256));
        AlterColumn("dbo.AspNetUsers","FirstName",c => c.String(nullable: false));
        AlterColumn("dbo.AspNetUsers","LastName",c => c.String(nullable: false));
        AddColumn("dbo.AspNetUsers","CreatedDateTime",c => c.DateTime(nullable: false));
        AlterColumn("dbo.AspNetRoles","Name",maxLength: 256));
        AddPrimaryKey("dbo.AspNetUserLogins",new[] { "LoginProvider","ProviderKey","UserId" });
        CreateIndex("dbo.AspNetUsers",unique: true,name: "UserNameIndex");
        CreateIndex("dbo.AspNetRoles",name: "RoleNameIndex");
        DropColumn("dbo.AspNetUsers","Discriminator");
    }