How to add in Linq to EF data in list form to Class Object C#?

Question

My class User is,

public class User
{
    public string Username
    {
        get;
        set;
    }
    public string Password
    {
        get;
        set;
    }
    public string [] RoleName
    {
        get;
        set;
    }
}

Linq to EF,

var innerJoinQuery =
                                (from u
                                in db.Users
                                join ur in db.UserRoles
                                    on u.UserID equals ur.UserID
                                join r in db.Roles on ur.RoleID equals r.RoleID
                                select new {
                                    Username=u.Username,
                                    Password=u.Password,
                                    RoleName = r.RoleName, }).ToList();

it result is,

Username = "Abc" Password="123"  RoleName = "Admin"
Username = "Test" Password="1234"  RoleName = "User"
Username = "Abc" Password="123"  RoleName = "Super User"

Manualy i add data in User class object,

List<Models.User> UserList = new List<Models.User>();
UserList.Add(new Models.User { Username ="Abc",Password="123",RoleName = new string[] {"Admin","Supe User"} });
UserList.Add(new Models.User { Username = "Test", Password = "1234", RoleName = new string[] { "User" } });

How to add linq to query data in List Object If you don not understand my question kindly let me know

Thanks

EDITED:

this is not hardcode for these values it can be more than this depend upon query result

Answer 1

Have you tried to instantiate anonymous types instead of Models.User ?

var resultList = (
       ...
       select new {
            Username=u.Username,
            Password=u.Password,
            RoleName = new [r.RoleName] }
   )
   .ToList();

resultList.Add(new {
            Username=u.Username,
            Password=u.Password,
            RoleName = r.RoleName })

Number and names of fields should be the same in both cases.

UPD

If you want to do it vise versa, than change your innerJoinQuery select statement to selecting Models.User , not an anonymous type:

var innerJoinQuery = (
       ...
       select new Models.User {
            Username=u.Username,
            Password=u.Password,
            RoleName = new [] {r.RoleName} // assuming you have string in database
       }
   )
   .ToList();

UserList.AddRange(innerJoinQuery);

If you want to join on local collection inside the query then, AFAIK it is not possible, cause EF will not be able to translate that to SQL.

UPD 2

Have missed that you have array in your Models.User and The array type 'System.String[]' cannot be initialized in a query result by your version of EF. so introducing a new Select after ToList is your way out:

var innerJoinQuery = (
       ...
       select new  {
            Username=u.Username,
            Password=u.Password,
            RoleName = r.RoleName
       }
   )
   .ToList()
   .Select(u => new Models.User {
            Username=u.Username,
            Password=u.Password,
            RoleName = new [] {r.RoleName}
       });

UserList.AddRange(innerJoinQuery);