extend linq entity-class constructor methods entity-class get it's datacontext class

is illusory extend linq-to-sql entity-classes constructor-methods same go; entity-class get it's data-context class?--in idea converting entity-class business object.

this settlement i am now using:

namespace xxx
{
    open category user : xxx.datacontext
    {
        open enum siteaccessrights
        {
            notregistered = 0,
            purebred = 1,
            executive = 3
        }

        private xxx.entities.user _user;

        open int32 id
        {
            get
            {
                relapse this._user.usersid;
            }
        }

        open xxx.user.siteaccessrights accessrights
        {
            get
            {
                relapse (xxx.user.siteaccessrights)this._user.usersaccessrights;
            }

            set
            {
                this._user.usersaccessrights = (int32)value;
            }
        }

        open twine alias
        {
            get
            {
                relapse this._user.usersalias;
            }

            set
            {
                this._user.usersalias = value;
            }
        }


        open user(int32 userid)
        {
            var user = (from u base.users
                        where u.usersid == userid
                        name u).firstordefault();

            (user != null)
            {
                this._user = user;
            }
            else
            {
                this._user = new xxx.entities.user();

                base.users.insertonsubmit(this._user);
            }
        }


        open user(xxx.user.siteaccessrights accessrights, twine alias)
        {
            var user = (from u base.users
                        where u.usersaccessrights == (int32)accessrights && u.usersalias == alias
                        name u).firstordefault();

            (user != null)
            {
                this._user = user;
            }
            else
            {
                this._user = new xxx.entities.user
                {
                    usersaccessrights = (int32)accessrights,
                    usersalias = alias
                };

                base.users.insertonsubmit(this._user);
            }
        }


        open vacant deleteonsubmit()
        {
            base.users.deleteonsubmit(this._user);
        }
    }
}

update:

notice i have twin constructor-methods user class. i'd send those user entity-class and extend user entity-class it's data-context class, data-context accessible entity-class "new-up".

hope creates sense.