Issue with Sub-query

Question

I have the following query:

SELECT  SP.PACKAGEID,SP.ORDERID,PTS.CREATIONDATE AS SHIPPEDDATE

FROM PACKAGES SP

INNER JOIN 

(
SELECT * FROM 
(
    SELECT *FROM PACKAGE_STATISTICS A 
    WHERE((A.PACKAGEID=SP.PACKAGEID)
    AND(A.PACKAGESTATUS=2)
    AND(TO_DATE(to_char(A.CREATIONDATE,'mm/dd/yyyy'),'mm/dd/yyyy') 
         BETWEEN TO_DATE('2/19/2011','mm/dd/yyyy') AND (TO_DATE('3/21/2011','mm/dd/yyyy'))))
    ORDER BY A.CREATIONDATE



) WHERE ROWNUM<2

) PTS ON PTS.PACKAGEID=SP.PACKAGEID
WHERE SP.ISSUEID IN(402783)

This query selects package details from PACKAGES table based on the following conditions:

1. The status of the packgae must be "Shipped".(Indicated by setting PACKAGESTATUS column of PACKAGE_STATISTICSto 2)
2. If there are multiple "Shipped" entries for a package, select the latest(based on CREATIONDATE column value).

When I run the above query it throwed ORA-00904 error as the subquery of level 2 refres the table name. So I have modified the query as given below:

SELECT  SP.PACKAGEID,SP.ORDERID, (SELECT CREATIONDATE FROM 

(
        SELECT *FROM PACKAGE_STATISTICSA 
        WHERE
((A.PACKAGEID=SP.PACKAGEID)
         AND(A.PACKAGESTATUS=2)
         AND(TO_DATE(to_char(A.CREATIONDATE,'mm/dd/yyyy'),'mm/dd/yyyy') 
             BETWEEN TO_DATE('2/19/2011','mm/dd/yyyy') AND (TO_DATE('3/21/2011','mm/dd/yyyy'))))
        ORDER BY A.CREATIONDATE
    ) WHERE ROWNUM<2) AS SHIPPEDDATE
FROM PACKAGESSP
WHERE 
(SHIPPEDDATE BETWEEN TO_DATE('2/19/2011','mm/dd/yyyy') 
    AND (TO_DATE('3/21/2011','mm/dd/yyyy'))) 
    AND   SP.ISSUEID IN(402783) 

It again throwed ORA-00904 SHIPPEDDATE Invalid Identifier. Please let me know how can I do this? Thanking you all, Pradeep

Answer 1

If you need only the latest date from PACKAGE_STATISTICS, why don't you simply use MAX(CREATION_DATE)? I can't test it right now, but you probably need a query like this:

SELECT SP.PACKAGEID
      ,SP.ORDERID
      ,MAX(A.CREATIONDATE) AS SHIPPEDDATE
  FROM PACKAGES SP
 INNER JOIN PACKAGE_STATISTICS A ON A.PACKAGEID = SP.PACKAGEID
 WHERE SP.ISSUEID IN (402783)
   AND A.PACKAGEID = SP.PACKAGEID
   AND A.PACKAGESTATUS = 2
   AND TO_DATE(to_char(A.CREATIONDATE, 'mm/dd/yyyy'), 'mm/dd/yyyy') BETWEEN
       TO_DATE('2/19/2011', 'mm/dd/yyyy') AND
       TO_DATE('3/21/2011', 'mm/dd/yyyy')
 GROUP BY SP.PACKAGEID
         ,SP.ORDERID

If you want more details from row of package_statistics with latest creationdate, consider using analytic functions:

SELECT SP.PACKAGEID
      ,SP.ORDERID
      ,PTS.*
  FROM PACKAGES SP
 INNER JOIN (SELECT ROW_NUMBER() OVER(PARTITION BY PACKAGEID ORDER BY CREATIONDATE DESC) rn
                   ,A.*
               FROM PACKAGE_STATISTICS A
              WHERE A.PACKAGESTATUS = 2
                AND TO_DATE(to_char(A.CREATIONDATE, 'mm/dd/yyyy')
                           ,'mm/dd/yyyy') BETWEEN
                    TO_DATE('2/19/2011', 'mm/dd/yyyy') AND
                    TO_DATE('3/21/2011', 'mm/dd/yyyy')) PTS ON PTS.PACKAGEID =
                                                               SP.PACKAGEID
                                                           AND PTS.RN = 1;