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    <p>You need to focus on mapping the entities themselves properly and then relations will just work. The conventions about keys are something along:</p> <ol> <li>If the entity has a property called Id it will be used as key</li> <li>If there is an EntityId (e.g. UserId) property then that is the key</li> <li>You need to specify what the key property is otherwise</li> </ol> <p>As to what column that key property corresponds to in the database, you can specify that using the Property() and HasColumnName() methods.</p> <p>Once this is done you don't have to worry about mapping keys in the relations mapping(well at least in your case one-to-one mapping).</p> <p>As to relationship mapping you don't have to define the relations both ways from User and from Profile. Once you define the relationship one way the other way is inferred. This keeps your code clean as well.</p> <p>The code below should help you understand the whole thing.</p> <pre><code>class Program { static void Main(string[] args) { // replace your connection string here using (var userContext = new UserContext("UserProfile")) { var u = new User { UserId = Guid.NewGuid(), Name = "John", Profile = new Profile() { ProfileId = Guid.NewGuid(), SomeValue = "x" } }; userContext.Users.Add(u); userContext.SaveChanges(); var users = userContext.Users.ToList(); foreach (var user in users) { Console.WriteLine(user.Name); if (user.Profile != null) { Console.WriteLine(user.Profile.ProfileId); } } var profiles = userContext.Profiles.Where(p =&gt; p.User.Name == "John").ToList(); } } } public class UserContext : DbContext { public UserContext(string connectionString) : base(connectionString) { } public DbSet&lt;User&gt; Users { get; set; } public DbSet&lt;Profile&gt; Profiles { get; set; } protected override void OnModelCreating(DbModelBuilder modelBuilder) { base.OnModelCreating(modelBuilder); modelBuilder.Entity&lt;User&gt;().Property(u =&gt; u.UserId).HasColumnName("ID"); modelBuilder.Entity&lt;Profile&gt;().Property(p =&gt; p.ProfileId).HasColumnName("ID"); modelBuilder.Entity&lt;User&gt;().HasOptional(u =&gt; u.Profile).WithRequired(p =&gt; p.User); } } public class User { public Guid UserId { get; set; } public string Name { get; set; } public Profile Profile { get; set; } } public class Profile { public Guid ProfileId { get; set; } public User User { get; set; } public string SomeValue { get; set; } } </code></pre>
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    1. POSetting up optional:required relationship Entity Framework - fluent API
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    1. COWhat you said is correct. The problem is that i want to have a UserId property in the Profile class (which is mapped to the FK column in the database) along with the User property.
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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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