Difference between RPG III and RPG IV with CHAIN

[jmmckee <jmmckee@xxxxxxxxxxxxxx>]

Where I work, training is something of a dirty word.

To read multiple records using a partial key in RPG III, I do this:

xxkey  chain   xxfmt                LR
*INLR  doweq  *OFF
  
  
xxkey  reade   xxfmt                         LR
           enddo


On a project a few years ago, written in RPG IV, that code did not work.

The only way we found to make it work was to do this:

xxkey    setll    xxfmt
xxkey     reade xxfmt                    
             dow    not %eof(xxfile)


xxkey    reade  xxfmt
             enddo


Doing a CHAIN to position and read the first record when multiple records were read just went to end of file, as I recall.  Been too long.

Were we doing someting wrong that caused the RPG IV code to fail?  This has really been bugging me for a long time.  I couldn't find a reason for the bizarre behavior in my searching.  It >may< have been an error when only one record with the matching subkey was found.  Again, I just don't remember.   

John McKee