MS Access SQL Query - Joining 3 Tables to receive Total Order Price - sql

Question

I would like to know the total price for a specific order ID. The information is contained in these tables:
Order_line_t
Order_ID Product_ID Quantity
-------- ---------- --------
1006 4 1
1006 5 2
1006 7 2
Uses_t
Product_ID Material_ID Footage
---------- ----------- -------
4 16 20
5 15 13
7 10 16
Raw_Materials_t
Material_ID Unit_Price
----------- ----------
16 05.70
15 16.72
10 15.55
The total cost is computed by
Multiplying SUM ( Order_line_t.Quantity * Uses_t.Footage * Raw_Materials_t.Unit_Price) AS Total
My current query only returns an error:
SELECT Order_line_t.Order_ID, Order_line_t.Product_ID, Uses_t.Product_ID ,Uses_t.Footage ,
SUM ( Order_line_t.Quantity * Uses_t.Footage * Raw_Materials_t.Unit_Price) AS Total
FROM Order_line_t, Uses_t , Raw_Materials_t
WHERE Order_line_t.Order_ID = 1006;
Help appreciated! How exactly do I JOIN these tables? What am i missing?

Answer 1

Firstly you were missing the actual joins between the tables, and secondly you were missing your group by
SELECT Order_line_t.Order_ID,
Order_line_t.Product_ID,
Uses_t.Product_ID ,
Uses_t.Footage ,
SUM ( Order_line_t.Quantity * Uses_t.Footage * Raw_Materials_t.Unit_Price) AS Total
FROM Order_line_t INNER JOIN
Uses_t ON Order_line_t.Product_ID = Uses_t.Product_ID INNER JOIN
Raw_Materials_t ON Uses_t.Material_ID = Raw_Materials_t.Material_ID
WHERE Order_line_t.Order_ID = 1006;
GROUP BY Order_line_t.Order_ID,
Order_line_t.Product_ID,
Uses_t.Product_ID ,
Uses_t.Footage
EDIT
Try this
SELECT Order_line_t.Order_ID,
Order_line_t.Product_ID,
Uses_t.Product_ID,
Uses_t.Footage,
Sum([Order_line_t].[Quantity]*[Uses_t].[Footage]*[Raw_Materials_t].[Unit_Price]) AS Total
FROM (Order_line_t INNER JOIN
Uses_t ON Order_line_t.Product_ID = Uses_t.Product_ID) INNER JOIN
Raw_Materials_t ON Uses_t.Material_ID = Raw_Materials_t.Material_ID
GROUP BY Order_line_t.Order_ID,
Order_line_t.Product_ID,
Uses_t.Product_ID,
Uses_t.Footage;
EDIT
Total by ORDER ID
SELECT Order_line_t.Order_ID,
Sum([Order_line_t].[Quantity]*[Uses_t].[Footage]*[Raw_Materials_t].[Unit_Price]) AS Total
FROM (Order_line_t INNER JOIN
Uses_t ON Order_line_t.Product_ID = Uses_t.Product_ID) INNER JOIN
Raw_Materials_t ON Uses_t.Material_ID = Raw_Materials_t.Material_ID
GROUP BY Order_line_t.Order_ID;

Answer 2

I think you need to compute the cost for each row, then sum the entire order. Something like:
select
Order_ID, sum(RowCost) as OrderCost
from (
select
o.Order_ID, o.Product_ID, o.Quantity,
u.Material_ID, u.Footage,
r.Unit_Price,
(o.Quantity * u.Footage * r.UnitPrice) as RowCost
from
order_line_t o INNER JOIN
uses_t u on o.Product_ID = u.Product_ID INNER JOIN
Raw_materials_t r on u.Material_ID = r.Material_ID
where
o.Order_ID = 1006
) z
group by
Order_ID