RE: Arrays

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

> From: Douglas W. Palme
> 
> The whole reason behind this question is that I have to create a
subfile
> that will display based on what salesman number the user enters, YTD
> hardgood sales (which is contained within the customer master file)
and
> then
> Cylinder rent which would be a cumulative amount from the line item
file
> (which contains 1.3 million records) and then a calculated field
showing
> the
> total, this has to be done for each different customer number assigned
to
> the salesman, and to top it off, I need the data displayed in
descending
> order LOL

Okay, let's take just a moment and break this down.

First, you need to process data in salesman/customer order.  As Bruce
mentioned, a single logical over the line detail by salesman/customer
will allow you to process this data.  You would use the SETLL command to
position the cursor at the beginning of the records for that salesman,
then read through the file using the READE command.  You would use
something we old-timers call "level break" logic to sum up the records
for each customer.

Now, if you were just showing it by salesman and customer, that would be
pretty simple.  The fly in the ointment is that you need to sort it by a
calculated field.  This is ALWAYS more difficult.  Back in the day,
there were basically three ways to do it:

1. A work file.  Write the records to the work file, which would then be
keyed by the appropriate value.

2. An array.  If you know the number of records will be small enough,
you can use an array.  Build an array of data structures then sort it.
In your case, since you're processing a single salesman, the maximum
number of entries would be the number of customers.

Okay, that's old school techniques.

Today, we would use embedded SQL.  The select would look something like
this (don't trust me on the syntax, there might be some grouping issues
and so forth, but you get the general idea):

SELECT CYLCUST, HARDYTD, SUM(CYLRENT) AS SUMRENT, HARDYTD+SUMRENT AS
TOTAL FROM CYLLIN, CUSMST WHERE CYLSLS = SLSMN AND CUST = CYLCUST GROUP
BY CYLCUST

Use this in a cursor and then read through it, writing each record to
the subfile.  For performance, you should still have the logical over
your line item file by salesman/customer.

Joe