In message <[log in to unmask]>, Bruce Hobbs 
<[log in to unmask]> writing at 13:13:48 in his/her local time 
opines:-
>On Sun, 20 Sep 2009 00:59:21 -0500, Michael <[log in to unmask]> wrote:
>
>>Before you call DBGET with mode=4, you should of previously called dbget
>>to read a record from this data set 'xxxx',  using mode 1, 2, 3, 5, 6,
>>or possibly 7. I don't know of any other way to retrieve a valid
>>RECORD-NUMBER.
>>
>I don't recall seeing such a requirement documented. Do you happen to 
>know the page number and version of the manual where you found that 
>requirement?

It's not a technical requirement as such (as I suspect you very well 
know :-) ).

It's more an indication that except, possibly, in the case of some 
extremely specifically arranged and maintained Image dataset, accessing 
record numbers 'blind' is unlikely to lead to any profitable result.

However, you certainly don't need to have previously read the actual 
record in question; a multi-level bill of materials, say, will store the 
next record at the current level (status elements 9 and 10) while 
exploding the current record (and possibly so on downwards recursively), 
repositioning itself at each returned level with a Mode 4 DBGET on the 
next in chain, and so on.

>>The program should have stored (MOVE) the RECORD-NUMBER to another
>>variable, eq MY-RECORD-NUMBER.

>>Before you call DBGET with mode=4, you'll first need to move
>>MY-RECORD-NUMBER to RECORD-NUMBER.

>Once a record number from the IMAGE status area has been stored in a 
>similarly-defined variable the DBGET argument parameter can directly 
>reference that variable.

Indeed so.

-- 
Roy Brown        'Have nothing in your houses that you do not know to be
Kelmscott Ltd     useful, or believe to be beautiful'  William Morris

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