Are complex SQL queries supported in ArcObjects?

Hello,

I'm wondering if a query like this is supported in ArcObjects?

string myquery = string.Format("Select p.portid, route_infoid From (Select route_infoid, x_id From route_items Where x_table = 'port') rit Inner Join (Select portid From port Where x_table = 'fibermngr' And x_id = {0}) p On p.portid = rit.x_id Group By p.portid, rit.route_infoid", XID);

Is it supported in all database formats, personal geodatabase, file geodatabase, sql and oracle? How do I go about using such a query? What objects support it? Are relationship classes required on the tables / data using such a query?

G