Brian,
I am assuming SOP (Sales Order Processing) orders, if that's not the case, please give some more detail.
For SOP, I have published a view you might find helpful that will return all SOP lines items for both posted and unposted transactions:
http://victoriayudin.com/2009/05/17/sql-view-with-all-sop-line-items/. Orders are SOPTYPE = 2, so you can filter on that if you need to.
If you simply want a quick query against the GP database, below are 2, one for open/unposted orders, another for historical/posted: