Verify Product Cost Rollup

All Products

select p1.product_class,p1.product_code,p1.description_1,p1.standard_cost, 
  sum(qty_assembly*p2.standard_cost) "Calc Std Cost", 
  (sum(qty_assembly*p2.standard_cost))-p1.standard_cost "Diff" 
from artprod p1 
inner join artprstr x on p1.product_code=x.assy_product_code inner join artprod p2 
     on x.comp_product_code=p2.product_code 
group by p1.product_class, p1.product_code,p1.description_1,p1.standard_cost order by 1 ,2
order by 1

Products with cost mis-match

select p1.product_class,p1.product_code,p1.description_1,p1.standard_cost,
  sum(qty_assembly*p2.standard_cost) "Calc Std Cost",
  (sum(qty_assembly*p2.standard_cost))-p1.standard_cost "Diff"
from artprod p1
inner join artprstr x on p1.product_code=x.assy_product_code
inner join artprod p2 on x.comp_product_code=p2.product_code
where abs(p1.standard_cost-
     (select sum(x2.qty_assembly*p3.standard_cost) from artprstr x2
     inner join artprod p3 on x2.comp_product_code=p3.product_code
     where p1.product_code=x2.assy_product_code ))> .0001
group by p1.product_class, p1.product_code,p1.description_1,p1.standard_cost
order by 1 ,2