title: EFcore with IdentityDbContext and hasData seeding creates IdentityRole
body: <p>I am a bit dazzled;
  I am using dotnet core  (2.1) EF with migrations. When I create the first migration just based upon the context, it all looks OK actually. </p>
  
  <p>so I have a context like:</p>
  
  <pre><code>public class DataContext : IdentityDbContext&lt;User, IdentityRole&lt;Guid&gt;, Guid&gt;
  {
  
      public virtual DbSet&lt;Country&gt; Countries { get; set; }
      public virtual DbSet&lt;CountryUser&gt; CountryUsers { get; set; }
      //..more stuff
  
      public DataContext(DbContextOptions options) : base(options)
      { }
  }
  </code></pre>
  
  <p>so after creating the migrations it wants to add: </p>
  
  <pre><code>migrationBuilder.CreateTable(
              name: "AspNetRoles",
              columns: table =&gt; new
              {
                  Id = table.Column&lt;Guid&gt;(nullable: false),
                  Name = table.Column&lt;string&gt;(maxLength: 256, nullable:
                  //etc. etc. Removed rest of migrations.
  </code></pre>
  
  <p>All good I thought.</p>
  
  <p>Then i started to follow the following article; 
  <a href="https://stackoverflow.com/questions/50785009/how-to-seed-an-admin-user-in-ef-core-2-1-0">How to seed an Admin user in EF Core 2.1.0?</a></p>
  
  <p>After setting the <code>HasData</code> and seeding the DB, created a new migration, it created a new migration where it wanted to drop the <code>AspNetRoles</code> table and creates as new table <code>IdentityRole</code>. 
  I just deleted the DB and tried to do it again, and now it only wants to insert the data when seeding. But i cannot figure out what I changed and even better, why it wanted to drop and create different tables.</p>
  
  <p>can somebody explain when it wants to create <code>AspNetRoles</code> and when it wants to create <code>IdentityRoles</code> (and along the other tables that goes with it).</p>
  
  <p>Just to be sure; the context was always extending from </p>
  
  <p><code>: IdentityDbContext&lt;User, IdentityRole&lt;Guid&gt;, Guid&gt;</code></p>
  
  <p>and my <code>User</code>:</p>
  
  <pre><code>public class User : IdentityUser&lt;Guid&gt;
  {
      public virtual ICollection&lt;CountryUser&gt; CountryUsers { get; set; }
  }
  </code></pre>
  
  <p>thnx!!</p>