Join Query Results

Question

i have a problem, i have a table were i keep the incoming and other one were i keep the outgoing records, the thing that i need to do is to group these records by partNumber and have a single output.

InTable

PartNo Qty Date
A       1   1/1/13
A       5   1/1/13
B       2   1/1/13

OutTable

PartNo Qty Date
A       2  1/1/13
B       1  1/1/13
C       3  1/1/13


Result Needed

Date 1/1/13

PartNo In Out Total
A      6   2    4
B      2   1    1
C      0   3    -3  

I have tried something like this but it results on the totals because of the sum(qty), but it does not work any other way.

select a.PartNo, sum(b.inQty) as inQty,sum(c.outQty) as outQty, sum(b.inQty)-sum(c.outQty) as total  from 
  (Select PartNo FROM InTable
  where date= '01-01-2013'
  group by PartNo
  union
  Select PartNo  FROM OutTable
  where date= '01-01-2013'
  group by PartNo) A
  cross join
  (  
  SELECT PartNo,SUM(Qty) inQty FROM InTable
  where date= '01-01-2013'
  group by PartNo
  )B
  cross join
  ( 
  SELECT PartNo,SUM(Qty) outQty FROM OutTable
  where date= '01-01-2013'
  group by PartNo
  )c
  group by a.PartNo

There i tried to join three queries, each query individually results in something helpfull, but the problem is when i try to join them, the query will result in something like

PartNo inQty outQty total 
A       8       6     2
B       8       6     2
C       8       6     2

Any sugestions?, thanks.

Answer 1

Use a Full Outer Join on two Derived Tables:

SELECT 
    COALESCE(inTab.PartNo, outTab.PartNo) AS PartNo,
    COALESCE(inQty, 0),
    COALESCE(outQty, 0),
    COALESCE(inQty, 0) -  COALESCE(outQty, 0) AS total
FROM 
 (
   SELECT PartNo, SUM(Qty) AS inQty 
   FROM InTable
   WHERE DATE= '01-01-2013'
   GROUP BY PartNo
 ) InTab
FULL JOIN
 (
   SELECT PartNo, SUM(Qty) AS outQty 
   FROM OutTable
   WHERE DATE= '01-01-2013'
   GROUP BY PartNo
 ) OutTab
ON inTab.Partno = outTab.PartNo