select		pt.default_code as drugcode,
			pt.name as drugname,
			sum(qt.quantity) as qty
from		product_template as pt
			left join product_product as pp 
on			pp.product_tmpl_id = pt.id
			left join stock_quant as qt 
on			pp.id = qt.product_id
			left join stock_location as sl 
on			sl.id = qt.location_id
where		pt.active = 'True'
			and pt.type = 'product'
			and sl.usage = 'internal'
group by	pt.default_code,
			pt.name;