MAX Function not returning MAX

Question

I have a query that is pulling in EDI 214 status codes, and want to pull in the last received status for status type "AG". To do this, I'm using the MAX function on the INSERT_DATE field of the status code AG, but the query keeps returning both AG status codes. I've tried this in a single query (Query 1) but it did not work so I also attempted it in a much smaller query to be used as a subquery, but that still did not work. Can anyone identify what the issue is with what I'm attempting to do?
Query 1 (All Inclusive):
SELECT BS.SHIPMENT_GID AS BUY_SHIPMENT_GID,
AGSS.EVENTDATE AS AG_EVENT,
D1SS.EVENTDATE AS D1_EVENT,
BS.START_TIME AS BUY_START_TIME,
AGSS.STATUS_CODE_GID AS AG,
D1SS.STATUS_CODE_GID AS D1,
BS.DOMAIN_NAME AS BUY_DOMAIN,
MAX(AGSS.INSERT_DATE) AS AG_INSERT_DATE,
MAX(D1SS.INSERT_DATE) AS D1_INSERT_DATE,
BS.START_TIME,
BS.DOMAIN_NAME,
SHIPSTAT.STATUS_VALUE_GID
FROM V_ROD_SHIPMENT BS
INNER JOIN V_ROD_SS_STATUS_HISTORY AGSH
ON (BS.SHIPMENT_GID = AGSH.SHIPMENT_GID)
INNER JOIN V_ROD_IE_SHIPMENTSTATUS AGSS
ON (AGSH.I_TRANSACTION_NO = AGSS.I_TRANSACTION_NO)
INNER JOIN V_ROD_SS_STATUS_HISTORY D1SH
ON (BS.SHIPMENT_GID = D1SH.SHIPMENT_GID)
INNER JOIN V_ROD_SHIPMENT_STATUS SHIPSTAT
ON (BS.SHIPMENT_GID = SHIPSTAT.SHIPMENT_GID)
INNER JOIN V_ROD_IE_SHIPMENTSTATUS D1SS
ON D1SH.I_TRANSACTION_NO = D1SS.I_TRANSACTION_NO
WHERE BS.START_TIME > '18/MAY/12'
AND BS.DOMAIN_NAME = 'UPS/CP/HDMB'
AND AGSS.STATUS_CODE_GID = 'AG'
AND D1SS.STATUS_CODE_GID = 'D1'
AND (SHIPSTAT.STATUS_VALUE_GID = BS.DOMAIN_NAME
|| '.SECURE RESOURCES_ACCEPTED'
OR SHIPSTAT.STATUS_VALUE_GID = BS.DOMAIN_NAME
|| '.SECURE RESOURCES_PICKUP NOTIFICATION')
GROUP BY BS.SHIPMENT_GID,
AGSS.EVENTDATE,
D1SS.EVENTDATE,
BS.START_TIME,
AGSS.STATUS_CODE_GID,
D1SS.STATUS_CODE_GID,
BS.DOMAIN_NAME,
SHIPSTAT.STATUS_VALUE_GID
Query 2 (to be used as a sub-query if I cannot pull MAX insert date in previous query):
SELECT DISTINCT BS.SHIPMENT_GID AS BUY_SHIPMENT_GID,
AGSS.EVENTDATE AS AG_EVENT,
AGSS.STATUS_CODE_GID AS AG,
MAX(AGSS.INSERT_DATE) AS AG_INSERT_DATE
FROM V_ROD_SHIPMENT BS
INNER JOIN V_ROD_SS_STATUS_HISTORY AGSH
ON (BS.SHIPMENT_GID = AGSH.SHIPMENT_GID)
INNER JOIN V_ROD_IE_SHIPMENTSTATUS AGSS
ON (AGSH.I_TRANSACTION_NO = AGSS.I_TRANSACTION_NO)
WHERE AGSS.STATUS_CODE_GID = 'AG'
AND BS.SHIPMENT_GID = 'UPS/CP/HDMB.HDM-1000203768'
GROUP BY BS.SHIPMENT_GID,
AGSS.EVENTDATE,
AGSS.STATUS_CODE_GID
Results of query 2 (similar issue as query 1, query doesn't return MAX insert date):
BUY_SHIPMENT_GID     AG_EVENT     AG     AG_INSERT_DATE
UPS/CP/HDMB.HDM-1000203768     5/25/2012 6:00:00 PM     AG     5/21/2012 3:10:36 PM
UPS/CP/HDMB.HDM-1000203768     6/1/2012 5:00:00 PM     AG     5/20/2012 2:36:18 PM
I appreciate any help.
Thanks,
-Adam

Answer 1

Hi, Adam,
Welcome to the forum!
Whenever you have a problem, please post a little sample data (CREATE TABLE and INSERT statements, relevant columns only) from all tables involved.
Also post the results you want from that data, and an explanation of how you get those results from that data, with specific examples.
Simplify the problem as much as possible. Remove all tables and columns that play no role in this problem.
If you can show what the problem is using commonly available tables (such as those in the scott schem) then you don't have to psot any sample data; just the results and the explanation.
Always say which version of Oracle you're using.
See the forum FAQ {message:id=9360002}
MAX (insert_date) returns the latest insert_date. I think, in this problem, you don't really want the latest insert_date; you want the status code that's related to the last insert_date. One way to get that is the aggregate FIRST (or LAST) function.
Consider this query, using the scott.emp table:
SELECT       ename
,       hiredate
FROM       scott.emp
ORDER BY  hiredate
,            ename
;Output:
ENAME      HIREDATE
SMITH      17-Dec-1980
ALLEN      20-Feb-1981
WARD       22-Feb-1981
JONES      02-Apr-1981
BLAKE      01-May-1981
CLARK      09-Jun-1981
TURNER     08-Sep-1981
MARTIN     28-Sep-1981
KING       17-Nov-1981
FORD       03-Dec-1981
JAMES      03-Dec-1981
MILLER     23-Jan-1982
SCOTT      19-Apr-1987
ADAMS      23-May-1987Say we're only interested in seeing the last hiredate, and the name of the person hired on that date:
LAST_ENAME LAST_HIREDA
ADAMS      23-May-1987Here's how to get those results using the aggregate LAST function:
SELECT       MIN (ename) KEEP (DENSE_RANK LAST ORDER BY hiredate) AS last_ename
,       MAX (hiredate)                                              AS last_hiredate
FROM       scott.emp
;What if there's a tie for the latest hiredate? For example, say we're only looking at people hired before 1982. In that case, the latest hiredate is December 3, 1981, and there happen to be two people hired on that date. This query
SELECT       MIN (ename) KEEP (DENSE_RANK LAST ORDER BY hiredate) AS last_ename
,       MAX (hiredate)                                              AS last_hiredate
FROM       scott.emp
WHERE         hiredate     < DATE '1982-01-01'
;produces only 1 row of output:
LAST_ENAME LAST_HIREDA
FORD       03-Dec-1981Why did it show FORD rather than JAMES? Because of the MIN function. When there happens to be a tie for the latest hiredate, MIN says to return the first ename (in normal sort order) of the rows that have that hiredate.
FIRST and LAST work with GROUP BY, too.
In the example above, we were only looking at one column related to the latest hiredate. If we neede to see several columns, it would be simpler to use the analytic ROW_NUMBER function:
WITH     got_r_num     AS
     SELECT  emp.*
     ,     ROW_NUMBER () OVER ( ORDER BY  hiredate  DESC
                               ,            ename
                       ) AS r_num
     FROM    scott.emp
     WHERE     hiredate     < DATE '1982-01-01'
SELECT     *
FROM     got_r_num
WHERE     r_num     = 1
I hope this answers your question.
If not, post a more complete explanation of what you want to do. if you have to use your own tables, then post CREATE TABLE and INSERT statements for a little sample data. Post the results you want from that data, and explain how you get those results from that data.