How to Sum the amounts for calculating rates.

Question

Hi,
I have a requirement in Apps 11i (OAB) that I need to code in PL/SQL. I would be calling a procedure in order to complete this task. When an Extract is run, this code gets executed and should return the amount for that person.
I need to calculate sum of all the amounts for each of the months between START date to the END date.
Ex: Amount = Amount + (for each of the months between START and END date) x Rate.
This START and END date would be calculated in the procedure itself.(dynamic).
Once we get the START date and END date, we need to loop thru some records and find person's rate between those START date and END date.
For rate calculation:
15th day of any month is used as the cut off date for rate calculation.
Suppose from 01-JAN-2006 to 15-MAR-2006 Rate is Rs 10 AND
16-MAR-2006 to 01-JUL-2006 rate is Rs 20 AND person died on 01-JUL-2006
Then rate = Rs(3x10) + Rs(3x20) + full month of July Rs.20 (P.S Here person's death needs to evaluated for the whole month) =30 + 60 + 20 = Rs.110
Typically the start date and end date would be in one particular YEAR. And person may have different rates for different amounts as mentioned above.
Let me if you need any more details..Thank You!
Additional Info:
This data comes from 2 tables in OAB Application where it can be joined with a common ID.
One table lets say Coverage table contains the usual columns Eff_start_date, Eff_end_date along with this it has Coverage_start_date and Coverage_end_date (Dates specifying duration of the person enrolled in particular coverage.)
P.S Rate Changes ONLY when the person enrolls in different coverage.
2nd Table lets say Rate table contains the usual columns Eff_start_date, Eff_end_date along with this it has rate_start_date and rate_end_date and RATE(column) for that duration.(may vary depending upon the coverage).
All the records should be between the START and END date, which will be calculated at runtime.
Unable to submit any sample records.:-(
Well, IF I had given the exact requirement, I would have got the solution by this Time!!! Your comments (and solutions) would definitely help me. Thank You
Message was edited by:
user559682

Answer 1

If i understand you correctly it can be possible with :
Connected to Oracle Database 10g Express Edition Release 10.2.0.1.0
Connected as hr
SQL>
SQL> drop table dates;
Table dropped
SQL> create table dates( "start" date, "end" date, "rate" number);
Table created
SQL> insert into dates values( to_date('01.01.2006', 'DD.MM.YYYY'), to_date('30.05.2006', 'DD.MM.YYYY'), 10);
1 row inserted
SQL> insert into dates values( to_date('01.06.2006', 'DD.MM.YYYY'), to_date('15.09.2006', 'DD.MM.YYYY'), 15);
1 row inserted
SQL> insert into dates values( to_date('16.09.2006', 'DD.MM.YYYY'), to_date('31.12.2006', 'DD.MM.YYYY'), 20);
1 row inserted
SQL> SELECT * FROM dates;
start       end               rate
01.01.2006  30.05.2006          10
01.06.2006  15.09.2006          15
16.09.2006  31.12.2006          20
SQL> SELECT t.i, d."rate"
  2    FROM (SELECT add_months(to_date('01.01.2006', 'DD.MM.YYYY') /* start*/, LEVEL - 1) i
  3            FROM dual
  4          CONNECT BY LEVEL <= 12) t
  5        ,dates d
  6   WHERE t.i BETWEEN d."start" AND d."end";
I                 rate
01.01.2006          10
01.02.2006          10
01.03.2006          10
01.04.2006          10
01.05.2006          10
01.06.2006          15
01.07.2006          15
01.08.2006          15
01.09.2006          15
01.10.2006          20
01.11.2006          20
01.12.2006          20
12 rows selected
SQL> SELECT SUM(d."rate") rs
  2    FROM (SELECT add_months(to_date('01.01.2006', 'DD.MM.YYYY') /* start*/, LEVEL - 1) i
  3            FROM dual
  4          CONNECT BY LEVEL <= 1 +
  5                     extract(MONTH FROM to_date('10.10.2006', 'DD.MM.YYYY') /*death*/) -
  6                     extract(MONTH FROM to_date('01.01.2006', 'DD.MM.YYYY') /* start*/)
  7          ) t
  8        ,dates d
  9   WHERE t.i BETWEEN d."start" AND d."end";
        RS
       130
SQL>