C/S Concurrency issue

From: D.W. Hoellein <hoellein_at_kersur.net>
Date: Tue, 12 May 1998 01:06:15 -0400
Message-ID: <3557D8C7.3FB1FDC4@kersur.net>

Our C/S system requires a unique id for each top-level object inserted into a table. We're using ODBC and are trying to stay fairly generic in our code, so we are maintaining the current id ourselves and incrementing as we insert new records.

Currently we SELECT the current id value, then UPDATE it to increment it for the next time. We have the problem of Client #1 obtaining the current value of N, but before it can UPDATE it to N+1, Client #2 also obtains the id of N. How can we insure that only one client will get a given value, without any other client getting it before the UPDATE occurs?

Thanks in advance!

Don Hoellein
Mantra Software Corp. Received on Tue May 12 1998 - 00:06:15 CDT