Daily max(value) query for time period

Question

I am looking to get the maximum value for every 24 hour period for a month. So for example my date range can be defined by...
select to_date('&date','mm yyyy')-1 + level as DateRange
from dual
connect by level <= '&days'
...where I can provide the first date of the month and number of days in the month or a lesser value if less time is required. So, the results of the above query plus 24 for the range. I thought a some googling would provide me what I needed, but my search came up empty.
I was hoping to do something like this...
select utctime, max(value) from table where utctime between....
Any guidance would be much appreciated!
Thanks!

Answer 1

Zewbie wrote:
Sorry about that...Oracle 10.2.0.5
create table x (utctime date,
pointnumber int,
value float)
insert into x values (to_date('02022012 232221','mmddyyyy hh24miss'), 10, 3.245);
insert into x values (to_date('02022012 202202','mmddyyyy hh24miss'), 13, 14.5);
insert into x values (to_date('02024012 103421','mmddyyyy hh24miss'), 10, 23.245);
insert into x values (to_date('02024012 042528','mmddyyyy hh24miss'), 10, 33.245);
insert into x values (to_date('02028012 022321','mmddyyyy hh24miss'), 14, 32.245);
insert into x values (to_date('02028012 205221','mmddyyyy hh24miss'), 10, 2.245);
insert into x values (to_date('02029012 211421','mmddyyyy hh24miss'), 14, 1.4345);
insert into x values (to_date('02029012 082221','mmddyyyy hh24miss'), 10, 3.245);Do you have dates 7000 years in the future, or ido you have typos?
So a query of the above would provide max daily value based on a pointnumber such as 10 for a given period.What are the results you want from the given data?
What role does pointnumber play in this problem?
If you want something like this:
A_DATE      POINTNUMBER  MAX_VALUE
02-Feb-2012          10      3.245
02-Feb-2012          13       14.5
02-Feb-2012          14
03-Feb-2012          10
03-Feb-2012          13
03-Feb-2012          14for the 2 days starting with February 2, 2012, then you can do this:
WITH   days_wanted     AS
     SELECT  DATE '2012-02-02'     -- starting date
              + LEVEL - 1     AS a_date
     FROM     dual
     CONNECT BY     LEVEL  <= 2     -- number of days wanted
SELECT    d.a_date
,       x.pointnumber
,       MAX (x.value)   AS max_value
FROM       days_wanted  d
LEFT OUTER JOIN        x  PARTITION BY (x.pointnumber)
                               ON  TRUNC (x.utctime)  = d.a_date
-- WHERE  x.pointnumber       = 10         -- If wanted
GROUP BY  d.a_date, x.pointnumber
ORDER BY  d.a_date, x.pointnumber
;