| Subject | Re: Record lock for unique # |
| From | Ken Mayer <dbase@nospam.goldenstag.net> |
| Date | Mon, 25 Mar 2019 06:52:55 -0700 |
| Newsgroups | dbase.getting-started |
On 3/21/2019 4:48 AM, Akshat Kapoor wrote: > On 21/03/2019 00:27, Randy Waldman wrote: >> Les - a simple and very informative reply. Thank you. No more than 4 >> users, so I s/b safe. >> >> Les Shewchuk Wrote: >> >>> Hi Randy, >>> >>> How many users and how frequent? >>> >>> I've used two techniques for this. >>> >>> 1. About a dozen users. All of the Counters (Quote, Order, PO, >>> Invoice) were in a single table. That table was left closed until a >>> number was needed. Then very quickly, >>> "Open-Fetch-Increment-Save-Close." Very rarely had an issue, but >>> there were glitches. I think it had to do with people fetching >>> different counters at the same time (Never did prove a cause) >>> >>> 2. As more user came on, I was also asked to add logs to the number, >>> starting with WHO and WHEN a number was issued. So each counter was >>> split into it's own table. Each Table started with an AutoInc field, >>> Name and DatetimeStamp (more Columns were added later). Again, the >>> tables were closed until needed. Then >>> "Open-Beginappend-StoreUser/Datetime-Save-get the new AutoInc >>> value-Close." This eliminated the conflict with two users going for >>> different counters at the same time and reduced the number of times >>> each of the counter's tables were being accessed. >>> >>> There is a routine in the DUFLP for setting a preferred value of an >>> AutoInc field. So you can reset them to Zero, or a desired start value. >>> > > I have been warned against using autoinc fields in dBase. There have > been some grave errors with some people and worst is autoinc field > cannot be edited to rectify the errors. We may be able to set the > autoinc field to desired values but that will always be for new rows not > for existing rows. This is rare (the issue involved), and has usually to do with importing data and not as much as every day use. Just because a couple of people had some issues does not mean that everyone else has. Ken -- *Ken Mayer* Ken's dBASE Page: http://www.goldenstag.net/dbase The dUFLP: http://www.goldenstag.net/dbase/index.htm#duflp dBASE Books: http://www.goldenstag.net/dbase/Books/dBASEBooks.htm dBASE Tutorial: http://www.goldenstag.net/dbase/Tutorial/00_Preface.htm | |