Re: CHAIN versus SETLL

[PaulMmn <PaulMmn@xxxxxxxxxxxxx>]

>In a message dated 97-05-22 20:44:05 EDT, you write:
>
>> IMO, in todays world of big iron, the answer is simple - code it the way
>>  that will make it the most readable.
>>  
>>  C    KEY    CHAINFILE            90
>>   *
>>  C    *IN90  IFEQ *ON
>>  .......etc.
>>  
>>  this makes it pretty obvious that the programmer has a complete key, and
>>  wants to know if "a particular" record exists or not.


Not necessarily, Kimosabee!  The AS/400 allows you to chain with a -partial-
key and match on the part you provide!  (I forget if this only works with a
composite key (ie more than 1 field) and if you have to use complete fields
as the partial key)

You do a CHAIN with a partial key, then a READE.  From a readability and
clarity point of view a SETLL/READE makes it more obvious exactly what
you're doing.

--Paul E Musselman
PaulMmn@ix.netcom.com

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