Comments on: AS/400 COBOL http://itknowledgeexchange.techtarget.com/itanswers/as400-cobol/ Fri, 24 May 2013 07:13:09 +0000 hourly 1 By: tomliotta http://itknowledgeexchange.techtarget.com/itanswers/as400-cobol/#comment-97470 tomliotta Wed, 05 Oct 2011 23:08:14 +0000 #comment-97470 If you only want to use a physical file (a ‘table’) and you program cannot know ahead of time which fields will be used as selection (key) fields out of six possible ones, there are three general possibilities.
  1. Use dynamic SQL. Specify a WHERE clause that provides whatever selection criteria is supplied.
  2. Read each each record and use IF-tests to see when records match.
  3. Use OPNQRYF to create a dynamic access path each time.

In each case, count the records until you reach 10. (With SQL you might use relative positioning.)

I suppose it’s also possible to use the C library functions such as _Rlocate() — Position a Record to retrieve specific records, but it’s not clear how you would use those when no appropriate access path existed (without creating one which seems to violate a “no LFs” rule.)

Tom

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