Using - Partition By in SQL report

Question

Our users are having problem with the below formula on Reports. I am not sure what this means. Our Users told that they need
(Tons Used/spread miles) * 2000 lb/ton = lbs/spread mile for their report.
And I see the below formula being used by our developer. Not sure how to read it though. Can any one let me know the formula used in the below code could actually represent the above formula. Users are complainting as below
from user ->column doubles or triples the amount if there are multiple records for the same truck/driver/beat/with the same amount for Dry Mat used and Spread Miles. If spread miles or the Dry Mat used is different if calculates correctly.
Edited by: Lucy Discover on Mar 28, 2011 1:50 PM

Answer 1

Hi,
Lucy Discover wrote:
Our users are having problem with the below formula on Reports. I am not sure what this means. Our Users told that they need
(Tons Used/spread miles) * 2000 lb/ton = lbs/spread mile for their report.
And I see the below formula being used by our developer. Not sure how to read it though. Can any one let me know the formula used in the below code could actually represent the above formula. Users are complainting as below
from user ->column doubles or triples the amount if there are multiple records for the same truck/driver/beat/with the same amount for Dry Mat used and Spread Miles. If spread miles or the Dry Mat used is different if calculates correctly.
SUM (ROUND ((NVL (sim_trip.dry_mat_used, 0)) /
nullif(sim_trip.spread_miles_total,0) * 2000, 2 ))
OVER (PARTITION BY sim_trip.trip_no,   sim_trip.dry_mat_code,        sim_trip.liquid_mat_code,
sim_trip.dry_mat_used,      sim_trip.liq_mat_used,         sim_trip.spread_miles_total
Yes, the code is basically implementing that formula. There's some code that hadles NULLs and rounds the amounts.
This is the analytic SUM function; the keyword OVER right after the argument indicates that. The difference (here) between the two forms is that the analytic SUM will work without a GROUP BY clause; you can show details about individual rows and the groupd total on the same output row, without doing a sub-query and a join. The analytic PARTITION BY clause correspdons to the aggregate GEOUP BY clause. Since you are saying:
...   OVER ( PARTITION BY  sim_trip.trip_no
                ,                 sim_trip.dry_mat_code
          ,                sim_trip.liquid_mat_code
          ,             sim_trip.dry_mat_used
          ,              sim_trip.liq_mat_used
          ,                 sim_trip.spread_miles_total
             )the ratio on any given row will only include rows with the same values of all 6 variables. It's very suspicious that two of those varibales (dry_mat_used and spread_miles_total) are also in the argument. That's legal, but it's very unusual.
Also, this is a sum or ratios, no a ratio of sums. That is, suppose, in some group, there are 2 rows. One row has 100 tons and 4 miles, while the other row has 100 tons and 1 mile. The formula you posted would repoert that as
(100 / 4) + ( 100 / 1) =
(25) + (100) =
125
and not
(100 + 100) / (4 + 1) =
(200) / (5) =
40
As you can see, there's a big difference. I don't know which one you want.
Whenever you have a problem, post a little sample data (CREATE TABLE and INSERT statements, relevant columns only) from all tables.
Also post the results you want from that data, and an explanation of how you get those results from that data, with specific examples.
Always say which version of Oracle you're using.