Re: Chain vs SetLL/ReadE

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
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