||Re: Record lock for unique #
Ken Mayer <email@example.com>
||Mon, 25 Mar 2019 06:52:55 -0700
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'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