Example, I have some groups and some items belong to these group. Now, I want to list items of arbitrary group by url like http://sp2010/Lists/items.aspx?groupid=1.
I maked a SPView like
SPView view = SPList.DefaultView;
view.Query = "<Where>
<Eq>
<FieldRef Name=\"Group\" LookupId=\"TRUE\">
<Value Type=\"Lookup\"><GetVar Name=\"GroupId\"></Value>
</Eq>
</Where>";
view.Update();
It work on sharepoint 2007, but unfortunately it don't work on sharepoint 2010.