Hello,

Is it possible to lock record to prevent editing it by other users without using TDataSet.Edit?

Regards
Mike

"Mike Mayer" <miko@gmail.com> wrote in message
news:97DDCD0B-AAEF-4712-8BF7-4700B569EC19@news.elevatesoft.com...
> Hello,
>
> Is it possible to lock record to prevent editing it by other users without
> using TDataSet.Edit?
>


If you have a unique record ID of 1000 or less, you can use semaphores.

Robert

Mike,

<< Is it possible to lock record to prevent editing it by other users
without using TDataSet.Edit? >>

Not really, no.  Why not just Edit the record - is there a particular reason
you don't want to use that method ?

--
Tim Young
Elevate Software
www.elevatesoft.com

"Tim Young [Elevate Software]" <timyoung@elevatesoft.com> wrote in message
news:7A061FFD-854F-4792-A17A-534BD7142498@news.elevatesoft.com...
> Mike,
>
> << Is it possible to lock record to prevent editing it by other users
> without using TDataSet.Edit? >>
>
> Not really, no.  Why not just Edit the record - is there a particular
> reason you don't want to use that method ?
>

Sometimes you have a hierarchichal database (I know, the concept shows MY
age) where you want to say "I'm going to be doing updates to this customer's
records, and nobody should touch the customer". You might not be changing
anything in the customer table per se, you just want to put a marker to
prevent anybody else from accessing any records related to this customer.

Robert

Exactly Robert!

I need to mark several records in database to prevent editing them.

>
> << Is it possible to lock record to prevent editing it by other users
> without using TDataSet.Edit? >>
>
> Not really, no.  Why not just Edit the record - is there a particular
> reason you don't want to use that method ?
>

Sometimes you have a hierarchichal database (I know, the concept shows MY
age) where you want to say "I'm going to be doing updates to this customer's
records, and nobody should touch the customer". You might not be changing
anything in the customer table per se, you just want to put a marker to
prevent anybody else from accessing any records related to this customer.

Mike

Why not simply have a field in the table which holds a flag saying if the record is being edited? Or have a separate table which holds a list of the records that are "locked"?

Roy Lambert

>>Why not simply have a field in the table which holds a flag saying if the record is being edited? Or have a separate table which holds a list of the records that are "locked"?

I thought that there is posibility to do this using native DBISAM functions, without using additional fields or tables.

"Mike Mayer" <miko@gmail.com> wrote in message
news:63C6D501-AD21-4881-AE1D-E1E8D9630DF6@news.elevatesoft.com...
>>>Why not simply have a field in the table which holds a flag saying if the
>>>record is being edited? Or have a separate table which holds a list of
>>>the records that are "locked"?
>
> I thought that there is posibility to do this using native DBISAM
> functions, without using additional fields or tables.
>
>

Like I said, if you have a unique number under 1000 in each record that
needs to be locked, you can add semaphore locking with just a few lines of
code. Otherwise, you can try to edit the "parent" record and catch the error
if anybody else is editing it, but you would also have to use pessimistic
locking, which IMO is a less desirable way to do things.

Robert

Mike


Nope. The "native" DBISAM locking system is table.edit

Roy Lambert

"Mike Mayer" <miko@gmail.com> wrote in message news:32EC0DC7-6E82-4362-B29E-3A724B52D169@news.elevatesoft.com...
> Exactly Robert!
>
> I need to mark several records in database to prevent editing them.
>
>>
>> << Is it possible to lock record to prevent editing it by other users
>> without using TDataSet.Edit? >>
>>
>> Not really, no.  Why not just Edit the record - is there a particular
>> reason you don't want to use that method ?
>>
>
> Sometimes you have a hierarchichal database (I know, the concept shows MY
> age) where you want to say "I'm going to be doing updates to this customer's
> records, and nobody should touch the customer". You might not be changing
> anything in the customer table per se, you just want to put a marker to
> prevent anybody else from accessing any records related to this customer.
>

The issue here is more Database & Application design

What is the nature of the records that you need to
prevent editing whilst you do the iterative update
and what is the relational structure exisiting around
those records that you can't lock a parent record

If you consider any update to be an instance of time
then you start to see that it matters not the state
of the data when you go to do your update

If A has already updated it prior to your update
then that state exists, if you do your update
before A then your state exists.

I can't see how either state can effect your decision to update
because if it does you have a serious application problem.

gF