Re: Chain vs SetLL/ReadE

[vhamberg@xxxxxxxxxxx]

Chandra

I happen to prefer this style for reading records in a loop, because you need to test only one function - %eof(fielname) - to me it is just simpler and cleaner.

Now if I am testing existence, I'll use SETLL with %equal(filename).

If I want only the one record, I'll use CHAIN with %found(filename) - yes, I could use the loop method, but I guess CHAIN says more to me what I'm doing - sort of self-documenting the process.

But for a loop, I like the suggested form. Or you could always go with a PRIMARY file and use the cycle!!  Just kidding - maybe!

HTH
Vern

-------------- Original message -------------- 
From: Chandra Krieg <chandrak@xxxxxxxxxxxxxx> 

> Hello all, 
>
> I have been told that the preferred method of random record retrieval is to use 
> the SetLL, then do a ReadE and check for the %EOF indicator. 
>
> Why is this preferred over using a Chain with %found or even checking for %Equal 
> on the SetLL before reading the file? I have been told that the Chain doesn't 
> do what I'm expecting it to but I've never had issues in the past. 
>
> I have read the archive posts and found opinions on the subject but no concrete 
> explenation as to why. As with some of the posts I don't understand why you 
> would want to readE the file if the SetLL didn't find an %equal match or why if 
> you plan to read the file a chain isn't appropriate. 
>
> I'm being told to use the following code instead of a Chain. 
>
> SetLL (KeyFields) FIleName; 
> ReadE (KeyFields FIleName; 
> DoW Not %EOF(FIleName); 
> do my stuff 
> ReadE (KeyFields) FileName; 
> EndDo; 
>
> Any explanations would be helpful! 
>
> TIA! 
>
> Chandra Krieg 
> i5 Programmer/Analyst 
> RateWatch 
> (P) 1.800.348.1831 ext 311 
> (F) 1.920.568.1403 
> www.rate-watch.com