Help in query required – Insert, Select in same table

Question

Hi All
I need your help on writing the queries effectively.
Oracle Version: 10.2.0.3.0
OS: UNIX
I have a table METRICS_TBL as mentioned below.
CYCLE_DATE     METRICS     VALUE
08/17/2008     COST-TV     100
08/17/2008     COST-NEWSPAPER     50
08/17/2008     COST-POSTALMAIL     25
08/17/2008     PROD-TV     10
08/17/2008     PROD-NEWSPAPER     25
08/17/2008     PROD-POSTALMAIL     5
Based on the above data, I need to append (Insert into METRICS_TBL select from METRICS_TBL) the same table with the records as mentioned below.
08/17/2008     COSTPERPROD-TV     10
08/17/2008     COSTPERPROD-NEWSPAPER     2
08/17/2008     COSTPER PROD-POSTALMAIL     5
Basically, I need to calculate Cost per Product for each category. Depending upon the available metrics, metrics also should be changed like COSTPERPROD and values should be Cost/prod under each category.
Can somebody help me with the query.
Thanks

Answer 1

SQL> WITH t AS
  2       (
  3          SELECT TO_DATE('8/17/2008', 'MM/DD/YYYY') AS CYCLE_DATE, 'COST-TV' AS METRICS, 100 AS VALUE
  4            FROM DUAL
  5          UNION ALL
  6          SELECT TO_DATE('08/17/2008', 'MM/DD/YYYY'), 'COST-NEWSPAPER', 50
  7            FROM DUAL
  8          UNION ALL
  9          SELECT TO_DATE('08/17/2008', 'MM/DD/YYYY'), 'COST-POSTALMAIL', 25
10            FROM DUAL
11          UNION ALL
12          SELECT TO_DATE('08/17/2008', 'MM/DD/YYYY'), 'PROD-TV', 10
13            FROM DUAL
14          UNION ALL
15          SELECT TO_DATE('08/17/2008', 'MM/DD/YYYY'), 'PROD-NEWSPAPER', 25
16            FROM DUAL
17          UNION ALL
18          SELECT TO_DATE('08/17/2008', 'MM/DD/YYYY'), 'PROD-POSTALMAIL', 5
19            FROM DUAL)
20  SELECT COST.CYCLE_DATE, 'COSTPERPROD-' || SUBSTR(COST.metrics, 6) AS Metrics,
21         COST.VALUE / prod.VALUE AS COSTPERPROD
22    FROM t COST, t prod
23   WHERE COST.CYCLE_DATE = PROD.CYCLE_DATE
24     AND COST.metrics LIKE 'COST-%'
25     AND prod.metrics LIKE 'PROD-%'
26     AND SUBSTR(COST.metrics, 6) = SUBSTR(prod.metrics, 6)
27  /
CYCLE_DA METRICS                                    COSTPERPROD
17.08.08 COSTPERPROD-NEWSPAPER                                2
17.08.08 COSTPERPROD-POSTALMAIL                               5
17.08.08 COSTPERPROD-TV                                      10