Difference of value of a dimension based on min and max

Question

Database: Oracle 10g
BO-BOXIr3
Let me explain the exact problem again.
As per the below code, I have the data in this format in my table:
Code:
Date              Site ID     KWH
1/2/2009 00:00     IN-1     22
1/2/2009 01:00     IN-1     28
1/3/2009 03:00     IN-2     25
1/3/2009 04:00     IN-2     46
1/4/2009 00:00     IN-3     28
1/4/2009 10:00     IN-3     34
1/5/2009 08:00     IN-4     31
1/5/2009 09:00     IN-4     55
1/5/2009 11:00     IN-4     77
1/6/2009 00:00     IN-5     34
Now want to build a report with following columns:
Site     Count     KWH
IN-1     2     6 (ex.-28-22)
IN-2     2     21
IN-3     2     6
IN-4     3     46 (ex.-77-31)
IN-5     2     34
SITE- distinct site name.
COUNT-count is number of repetitions of site id between min and max date.
KWH -(Delta between the min and max date)
To get the above result I have created 3 report from different queries since not able to get these al in a single report viz Count, Max Value and Min value. Well I have all these 3 reports or table on a single page.
Count-this report will give the count between the dates
Max Value-this report will give me the values of kwh for max dates for each site id
Min Value-this report will give me the values of kwh for min dates for each site id
Now want to create a single report based on these 3 reports which contains the column
Site|Count|KWH
IS IT POSSIBLE?
Or
Is it possible to build such report in a single one with all the required column which I mentioned?
The variables which I created to get the max & min dates,
Mx_dt= =Max([Query 2].[Hourly]) In ([Query 2].[SITE_ID])
Mn_dt= =Min([Query 3 (12)].[Hourly]) In ([Query 3 (12)].[SITE_ID])
For filtering on report used following variables:
if_st_mn=If([mn_dt])=[Hourly] Then "ok" Else "no"
if_st_mx =If([mx_dt])=[Hourly] Then "ok" Else "no"
will filter on "ok" to get the max and min date values.
rest of the variable in the snap are not usable.

Answer 1

Yes, you can do it in one report.
I created a sample report from efashion:
Year | Lines | Sales Revenue
2001 | Accessories | $250
2003 | Accessories | $550
2001 | City Skirts | $1050
2003 | City Skirts | $1150...........
Create 2 variables 1) Count and 2) Difference:
1) Count  as formula - =Count([Lines]) In Report
2) Difference as formula - =Sum([Sales revenue]) Where (Max([Year]) In Report = [Year]) - Sum([Sales revenue]) Where (Min([Year]) In Report = [Year])
You can replace the formula with your report variables. Then just drag Site ID, Count and Difference variables to your report.
Thanks
Jai