Help with select statement

Question

Hello,
My table looks similar to this, I have removed a few columns:
table1:
Forecast_id Forecast_name Freeze Enabled
100 Q12009 N Y
101 Q22009 N Y
table2:
forecast_id parameter_name parameter_value
100 StartDate 01/01/2009
100 EndDate 03/31/2009
100 Growth % 20
100 Retailer Walmart
101 StartDate 04/01/2009
101 EndDate 06/30/2009
101 Growth % 20
101 Retailer Walmart
What i need to do is
select from table 1, forecast name & freeze
where in table2 parameter = Retailer, Parameter value = Walmart and
Start Date = 01/01/2009 and End Date = 03/31/2009
here is my query is there a easy way this can be done. I have used decode function in the past for similar situation for counting and grouping.
SELECT i.FORECAST_ID,
i.FORECAST_NAME,
i.FREEZE_FLAG
FROM (
SELECT x.FORECAST_ID,
x.FORECAST_NAME,
x.FREEZE_FLAG
FROM (
SELECT A.FORECAST_ID,
A.FORECAST_NAME,
A.FREEZE_FLAG
FROM GC_FORECAST A, GC_FORECAST_PARAMETERS B
WHERE A.FORECAST_ID = B.FORECAST_ID
AND B.PARAMETER_NAME = 'Retailer'
AND B.PARAMETER_VALUE = 'Walmart'
) x, GC_FORECAST_PARAMETERS y
WHERE x.FORECAST_ID = y.FORECAST_ID
AND y.PARAMETER_NAME = 'StartDate'
AND y.PARAMETER_VALUE = '01/01/2009'
) i, GC_FORECAST_PARAMETERS j
WHERE i.FORECAST_ID = j.FORECAST_ID
AND j.PARAMETER_NAME = 'EndDate'
AND j.PARAMETER_VALUE = '03/31/2009';
Thank you for your time and help.
Vidhya
Edited by: snaraya9 on Dec 5, 2008 12:03 PM
Edited by: snaraya9 on Dec 5, 2008 12:06 PM

Answer 1

Solution
SELECT gc_forecast.forecast_id, gc_forecast.forecast_name, gc_forecast.freeze,
       gc_forecast.enabled
  FROM gc_forecast,
       (SELECT   forecast_id,
                 MAX (CASE
                         WHEN parameter_name = 'StartDate'
                         AND parameter_value = '01/01/2009'
                            THEN 1
                         ELSE 0
                      END
                     ) cond1,
                 MAX (CASE
                         WHEN parameter_name = 'EndDate'
                         AND parameter_value = '03/31/2009'
                            THEN 1
                         ELSE 0
                      END
                     ) cond2,
                 MAX (CASE
                         WHEN parameter_name = 'Retailer'
                         AND parameter_value = 'Walmart'
                            THEN 1
                         ELSE 0
                      END
                     ) cond3
            FROM gc_forecast_parameters
        GROUP BY forecast_id) gf
WHERE gc_forecast.forecast_id = gf.forecast_id
   AND gf.cond1 = 1
   AND gf.cond2 = 1
   AND gf.cond3 = 1
Demo
SQL*Plus: Release 10.1.0.4.2 - Production on Ven. Déc. 5 15:34:14 2008
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
Connecté à :
Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options
SQL> /* Formatted on 2008/12/05 15:33 (Formatter Plus v4.8.8) */
SQL> WITH gc_forecast_parameters AS
  2       (SELECT 100 forecast_id, 'StartDate' parameter_name,
  3               '01/01/2009' parameter_value
  4          FROM DUAL
  5        UNION ALL
  6        SELECT 100, 'EndDate', '03/31/2009'
  7          FROM DUAL
  8        UNION ALL
  9        SELECT 100, 'Growth', '% 20'
10          FROM DUAL
11        UNION ALL
12        SELECT 100, 'Retailer', 'Walmart'
13          FROM DUAL
14        UNION ALL
15        SELECT 101, 'StartDate', '04/01/2009'
16          FROM DUAL
17        UNION ALL
18        SELECT 101, 'EndDate', '06/30/2009'
19          FROM DUAL
20        UNION ALL
21        SELECT 101, 'Growth', '% 20'
22          FROM DUAL
23        UNION ALL
24        SELECT 101, 'Retailer', 'Walmart'
25          FROM DUAL),
26       gc_forecast AS
27       (SELECT 100 forecast_id, 'Q12009' forecast_name, 'N' freeze, 'Y' enabled
28          FROM DUAL
29        UNION ALL
30        SELECT 101, 'Q22009', 'N', 'Y'
31          FROM DUAL)
32  SELECT gc_forecast.forecast_id, gc_forecast.forecast_name, gc_forecast.freeze,
33         gc_forecast.enabled
34    FROM gc_forecast,
35         (SELECT   forecast_id,
36                   MAX (CASE
37                           WHEN parameter_name = 'StartDate'
38                           AND parameter_value = '01/01/2009'
39                              THEN 1
40                           ELSE 0
41                        END
42                       ) cond1,
43                   MAX (CASE
44                           WHEN parameter_name = 'EndDate'
45                           AND parameter_value = '03/31/2009'
46                              THEN 1
47                           ELSE 0
48                        END
49                       ) cond2,
50                   MAX (CASE
51                           WHEN parameter_name = 'Retailer'
52                           AND parameter_value = 'Walmart'
53                              THEN 1
54                           ELSE 0
55                        END
56                       ) cond3
57              FROM gc_forecast_parameters
58          GROUP BY forecast_id) gf
59   WHERE gc_forecast.forecast_id = gf.forecast_id
60     AND gf.cond1 = 1
61     AND gf.cond2 = 1
62     AND gf.cond3 = 1;
FORECAST_ID FORECA F E
        100 Q12009 N Y
SQL>