c# - Which approach to use on a provider with entity framework? -

i have class:

public class tool {     [edmscalarpropertyattribute(entitykeyproperty=true, isnullable=false)]     [datamemberattribute()]     public int64 id { get; set; }      [edmscalarpropertyattribute(entitykeyproperty=false, isnullable=false)]     [datamemberattribute()]     public string name { get; set; } } 

my provider has 2 methods:

public ienumerable<tool> getfirst() {     using (var db = new entitites())     {         return db.tools.firstordefault();     } }  public void update(tool o) {     using (var db = new entities())     {         db.tools.savechanges();     } } 

it doesn't work because on different contexts, parameter on update method not being used. can object database , change fields 1 one parameter object save changes.

what should do?

• update object , save?
• keep 1 context on providers?
• another approach?

i found attach method another question, quite similar

using (var db = new entitites()) {     // attach object on context     db.attach(tool);      // change state of context ensure update     db.objectstatemanager.getobjectstateentry(tool).setmodified();      // clientwins, flawless victory     db.refresh(refreshmode.clientwins, tool); }