c# - Separating IdentityUser from UserProfile -

i split user-details it's own table profile foreign key applicationuser, inserts fail.

so got following tables:

aspnetusers  {     id     username     passwordhash     securitystamp     descriminator } 

and

profiles {     id     firstname     lastname     email     aspnetuser_id } 

so changed registerviewmodel adding fields this:

public class registerviewmodel {     [required]     [display(name = "user name")]     public string username { get; set; }      [required]     [stringlength(100, errormessage = "the {0} must @ least {2} characters long.", minimumlength = 6)]     [datatype(datatype.password)]     [display(name = "password")]     public string password { get; set; }      [datatype(datatype.password)]     [display(name = "confirm password")]     [compare("password", errormessage = "the password , confirmation password not match.")]     public string confirmpassword { get; set; }      [required]     [display(name = "first name")]     public string firstname { get; set; }      [required]     [display(name = "last name")]     public string lastname { get; set; }      [required]     public string email { get; set; } } 

... , incorporated fields profiles table register.cshtml , want store information model 2 tables. accountcontroller.register looks this:

    //     // post: /account/register     [httppost]     [allowanonymous]     [validateantiforgerytoken]     public async task<actionresult> register(registerviewmodel model)     {         if (modelstate.isvalid)         {              var user = new applicationuser() { username = model.username };             var result = await usermanager.createasync(user, model.password);              if (result.succeeded)             {                 var profile = new profile                 {                     firstname = model.firstname,                     lastname = model.lastname,                     email = model.email,                     user = user                 };                  var db = new decoupledb();                 db.profiles.add(profile);                 db.savechanges();                  await signinasync(user, ispersistent: false);                 return redirecttoaction("index", "home");             }             else             {                 adderrors(result);             }         } 

but keep getting error on

db.savechanges(); 

the error saying im trying violate primary key of aspnetusers table

"violation of primary key constraint 'pk_dbo.aspnetusers'. cannot insert duplicate key in object 'dbo.aspnetusers'. duplicate key value (372775e0-bad5-452f-b65c-cd9bf7b80b34). statement has been terminated."

and cant understand why, because it's foreign key when add profile aspnetuser should not created, or thought.

anyone see fix?

i found answer. have store new user, fetch , populate profile. this:

        if (modelstate.isvalid)         {             var user = new applicationuser {username = model.username};             var result = await usermanager.createasync(user, model.password);              if (result.succeeded)             {                 var newuser = db.applicationusers.find(user.id);                  var profile = new profile                 {                     firstname = model.firstname,                     lastname = model.lastname,                     email = model.email,                     identity = newuser,                 };                  db.profiles.add(profile);                 db.savechanges();                  await signinasync(user, ispersistent: false);                 return redirecttoaction("index", "home");             }             else             {                 adderrors(result);             }         }