Optimising SQL statement to use query but need to reference column outside subquery somehow

Question

Is there any way in Oracle within an SQL query to reference a column from within a subquery that is outside of it, or to achieve that effect even if via a different means? Everything I've read on the web so far has just not helped with this.

For example (this is the kind of thing I'm after):

SELECT a.product_code, b.received, b.issued
FROM productinfo a,
 (SELECT SUM(qty_received) AS received, SUM(qty_issued) AS issued
  FROM productdetail b WHERE b.product_code = a.product_code AND active = 1);

I've tried loads of different variations/combinationsAt the moment I just get errors like ORA-00904: invalid identifier relating to the WHERE clause relationship.

At present if I run as seperate queries, e.g.:

SELECT product_code FROM productinfo;

and then for each of those records:

SELECT SUM(qty_received) AS received, SUM(qty_issued) AS issued FROM productdetail
WHERE product_code = '(specified)' AND active = 1;

This can take over an half an hour to run for 8000 records which is just plain daft.

Running out of hair, any help appreciated!! Thank you.

Answer 1

The ORA error is because you can't correlate the derived table/inline view - you need to use JOIN notation (ANSI-89 or 92).

Assuming you really need column(s) from the PRODUCTINFO table, use:

SELECT a.product_code, b.received, b.issued
  FROM PRODUCTINFO a
  JOIN (SELECT t.product_code,
               SUM(t.qty_received) AS received, 
               SUM(t.qty_issued) AS issued
          FROM PRODUCTDETAIL t 
         WHERE t.active = 1
      GROUP BY t.produce_code) b ON b.product_code = a.product_code

If you want to see a list of the productinfo records, which may or may not have PRODUCTDETAIL records, use:

   SELECT a.product_code, b.received, b.issued
     FROM PRODUCTINFO a
LEFT JOIN (SELECT t.product_code,
                  SUM(t.qty_received) AS received, 
                  SUM(t.qty_issued) AS issued
             FROM PRODUCTDETAIL t 
            WHERE t.active = 1
         GROUP BY t.produce_code) b ON b.product_code = a.product_code

But the example looks like you might only need to use:

 SELECT t.product_code,
        SUM(t.qty_received) AS received, 
        SUM(t.qty_issued) AS issued
   FROM PRODUCTDETAIL t 
   WHERE t.active = 1
GROUP BY t.produce_code

Answer 2

Just group by inside the query and use an inner join

SELECT a.product_code, b.received, b.issued
FROM productinfo a
INNER JOIN
 (SELECT product_code, SUM(qty_received) AS received, SUM(qty_issued) AS issued
  FROM productdetail
  WHERE active = 1
  GROUP BY product_code) b on b.product_code = a.product_code