Possible Join Issue

Question

I have the following query, part of which I inherited from elsewhere. The table aliased c has 47,000 records in it. What I want to do is select one each of these records by CVBI_KEY (47,000) unique CVBI_KEYS. There is information in other tables as seen that will make up the result set. All I wan to do is look up the information in these other tables, looking for the uniquie CVBI_KEY and the date, which signifies a unique run. The result should be 47,000 record, but it is 50,000. If I put a DISTINCT in there, it goes back to 47,000. There must be something amiss in my joins, but I think I am just patching with a band-aid if I use the distinct, and I think this is causing me problems elsewhere.
SELECT
       C.CVBI_KEY
     , C.CONDENSED_EC_CIRCUIT || C.VENDOR_ID
     , DECODE( C.SEND_LCA, 'YES', C.VENDOR_ID || 'XX' , C.VENDOR_ID || SUBSTR(C.ZLOC, 5, 2) )
     , CR.BILLING_ACCOUNT_ID
     , CR.BAN
     , C.CONDENSED_EC_CIRCUIT
     , C.VENDOR_ID
     , C.CIRCUIT_TYPE
     , CT1.ACTIVITY_CD
     , DECODE( C.SEND_LCA , 'YES', 'XXXXXXXX', C.ALOC )
     , DECODE( C.SEND_LCA , 'YES', 'XXXXXXXX', C.ZLOC )
     , DECODE( C.SEND_LCA , 'YES', 'XXXXXXXX-XXXXXXXX', NVL(AZ.MASTER_ROUTE_NAME, AZ.REVERSED ))
     , DECODE( C.SEND_LCA, 'YES', 'XXX', VENDOR_OCN(C.VENDOR_ID) )
     , DECODE( C.SEND_LCA, 'YES', 'XX', SUBSTR(C.ZLOC,5,2) )
     , '&&CUR_PERIOD'
     , TO_CHAR(SYSDATE)
FROM
       RCO.RPT_DS1_CNT_CAT C
     , RCO.COGS_RESOURCE CR
     , RCO.COGS_T1ACTIVITY CT1
     , RCO.RPT_DS1_ALOC_ZLOC_REVERSE_VW AZ
WHERE (C.CVBI_KEY = CR.CVBI_KEY (+)
AND  CR.PERIOD = '&&CUR_PERIOD')
AND  (C.CVBI_KEY = CT1.CVBI_KEY (+)
AND CT1.PERIOD = '&&CUR_PERIOD')
AND (AZ.MASTER_ROUTE_NAME=C.ALOC||'-'||C.ZLOC OR AZ.REVERSED=C.ALOC||'-'||C.ZLOC);Just when I think I understand the joins, I come up with something that shows me I don't. By the way, this is 8i and the INNER JOIN, LEFT OUTER JOIN syntax is not available.

Answer 1

There are a couple of possibilities.
One or both of rco.cogs_resource and rco.cogs_t1activity has more than one record for some combination of cvbi_key and period. That is, cvbi_key and period are not unique in those tables. You can check this by something like:
SELECT cvbi_key, period, count(*) FROM rco.cogs_resource
WHERE period = '&durr_period'
GROUP BY cvbi_key, period
HAVING count(*) > 1If this query on either table returns rows, you need to add some criteria to get only single rows from those tables.
The other possibility is that you have something like this. Here, t is your rco.rpt_ds1_cnt_cat and t1 is rpt_ds1_aloc_zloc_reverse_vw.
SQL> SELECT * FROM t;
ALOC       ZLOC
ABCD       EFGH
WXYZ       STUV
SQL> SELECT * FROM t1;
MASTER               REVERSED
ABCD-EFGH            EFGH-ABCD
WXYZ-STUV            STUV-WXYZ
STUV-WXYZ            WXYZ-STUV
SQL> SELECT t.aloc, t.zloc, t1.master, t1.reversed
  2  FROM t, t1
  3  WHERE t1.master = t.aloc||'-'||t.zloc or t1.reversed=t.aloc||'-'||t.zloc;
ALOC       ZLOC       MASTER               REVERSED
WXYZ       STUV       STUV-WXYZ            WXYZ-STUV
ABCD       EFGH       ABCD-EFGH            EFGH-ABCD
WXYZ       STUV       WXYZ-STUV            STUV-WXYZIf this is true, we probably botched the view definition on you :-)
John