Re: Conceptual subfile question

[Booth Martin <booth@xxxxxxxxxxxx>]

I do not understand the technique then.  Where is the original data 
kept?  A user reads 55 records into a subfile and then changes record 
number 22. Where, exactly, is the original data for subfile record # 22 
stored, if not in a hidden field?

On 5/3/2016 3:46 PM, Jon Paris wrote:
> Yes Booth - you can also do it that way - but you’re not answering the same question then.
>
> Comparing before/after display images tells you whether _your_ operator made changes on the screen.
>
> Comparing previous/current disk images tells you whether somebody else changed the record while you were waiting for the operator to decide what they donated to do.
>
> You can of course combine both techniques.  I should have mentioned that the article was dealing with not holding prolonged locks on the database but the same basic “image” technique works just fine as a means of avoiding hidden fields.
>
>
> Jon Paris
>
> www.partner400.com
> www.SystemiDeveloper.com