Create, Read, Update, Delete (CRUD) operations with Entity Framework in C#

public void createUser(string _name, string _phone){

   User u = new User();
   u.Name = _name;
   u.Phone =_phone;
        
   DatabaseEntities de = new DatabaseEntities();
   de.AddObject("Users",u);
   de.SaveChanges();

 }

public string searchUser(int _id){
 
   DatabaseEntities de = new DatabaseEntities();

   var query = from o in de.Users where o.Id==_id select o;        
   string str = "";

   foreach (User u in query){
           
        str = "ID: " + u.Id + " " + u.Name + " " + u.Phone;         
           
   }
 
return str;
}

public void updateUser(int _id,string _name,string _phone){

   DatabaseEntities de = new DatabaseEntities();
   User u =de.Users.Where("it.Id=" + _id).First();
   u.Name = _name;
   u.Phone =_phone;        
   de.SaveChanges();

}

public void deleteUser(int _id){

   DatabaseEntities de = new DatabaseEntities();
   User u = de.Users.Where("it.Id=" + _id).First();
   de.DeleteObject(u);
   de.SaveChanges();

}

protected void btnCreate_Click(object sender, EventArgs e){
      
   string name = txtName.Text;
   string phone = txtPhone.Text;

   createUser(name,phone);

   txtName.Text = "";
   txtPhone.Text = "";
}