Can't add row in Database using WCF Service

Question

Can someone give me any help with this problem:

I have a database built with entity framework. In my simple project, all I'm trying to do is to add a new row in the database, that's all.

I have one class for the database, named UserDB

public class UserDB : DbContext
{
    public UserDB()
        : base("UserDB")
    {

    }

    public List<User> Users { get; set; }
}

and class for the User

[Table(Name="User")]
public class User
{
    [Key]
    public String Name { get; set; }
}

I'm trying to add a new data in the database with another Console application, but every time I invoke the method insertInformation(string name) it says that the List of Users in UsersDB is null, and can't add the new User in the database. I used the same method in other ASP.NET application and it all work perfect. If someone have idea how to solve this, please help

The service I'm using:

public class Service1 : IService1
{

    /// <summary>
    /// Method for adding new User in Database
    /// </summary>
    /// <param name="name"></param>
    public void insertData(string name)
    {
        UserDB db = new UserDB();
        User user = new User
        {
            Name = name
        };
        //if (db.Users == null)
        //{
        //    db.Users = new List<User>();
        //    db.Users.Add(user);
        //}
        //else
        //    db.Users.Add(user);

        db.Users.Add(user);
        db.SaveChanges();
    }

Answer 1

Maybe you should try using the following code:

Instead of:

List<User> Users { get; set; }

Simply try:

DbSet<User> Users { get; set; }

I always use DbSet or IDbSet in my DBContext's and it always works.

Answer 2

Use this

db.Users.InsertAllOnSubmit(user);
db.SubmitChanges();

Instead of

 db.Users.Add(user);
 db.SaveChanges();

Answer 3

try this

db.AddObject("User", user);
db.SaveChanges();