Re: check for record changed between read/chain(n) and update

What I do is have three data structures named "Record", "OriginalRecord" and "NewRecord", all defined like the record format. Then I prefix two of the data structures as "O_" & "N_" Then, on the original read I eval OriginalRecord = Record. Then, later just before I do the locking read I move the Record (which now has the new values) into NewRecord, If NewRecord = Original then there are no proposed changes, so bail out.
Otherwise do the locking read and again compare the Record to Original Record.
If the Original is *not* equal to the Record then there have been changes at another workstation, do as is appropriate to the business rules.
If the Original is equal to the Record then its is safe to make the change, so eval Record = NewRecord and do the update.

Seems to work fast and is really handy if you also are using F5=Refresh (Record = OriginalRecord) to let the user undo changes and start over.



Gene Burns wrote:

I need to change a program to get a record from a file chain(n) and let the
user work with the data, go to other programs, return to the original
calling program, etc., then if the user makes changes to the data I need to
check whether the record has changed before updating.

Is there a better way to do this than bringing the data record into a data
structure chain(key) file DSname and then rewriting the entire program to
use the qualified field names from the DS?

I am concerned that even if I do this, that the record could be updated in
between the chain to get the record into a DS for comparison to the original
DS and the actual update.

Gene