Using this method; you *rearly* get record lock errors because as the
user is editing the record on his form the actual database record is not
actually locked; because i've pulled the data from the record using a
select and thrown it into my editing components.
On the instant when the user clicks the post button is where everything
happens; for mission critical applications i change the tag of each edit
control when the data is changed so i know exactly which fields to post
into the database - this prevents one user changing then another user's
data overwriting it.
A simple way would be to do your own locking; adding a fiend called
edit_stat which is normally 0 but changes to 1 when a user is editing
the record. When another user hits edit and the field is 1 it could deny
editing to avoid a deadlock.
I have totally zero experience with nexusdb so its kind of a problem
coming up with a solution. Any url?
J
Nesler, Thomas J wrote:
> Hi Jangita!
>
> Your post does help me organize my thoughts. If I understand you
> correctly, you don't use Dbaware components but when a user clicks a
> button you fetch the data and fill the form with it or Post the changes
> to the record. What code do you use to determine if a record is locked
> for editing?
>
> What I am looking for is an example or two on how to handle deadlocks or
> other kinds of locks on a record.
>
> Tom Nesler
>
> Live long!... Code Well!... and Prosper!... V
>
>
> -----Original Message-----
> From: [email protected] [mailto:[EMAIL PROTECTED] On
> Behalf Of jangita
> Sent: Wednesday, April 26, 2006 3:50 PM
> To: [email protected]
> Subject: Re: [delphi-en] Using the TTable Edit Error Event
>
>
> Hello
>
> I have done quite a bit of multi user client server programming and the
> following is a method i have found that works best
>
> 1. when the user wants a list of items; i call a select stored procedure
>
> which returns the information; this is stored in a normal query
> component
> 2. i *never* use data aware components; when the user clicks edit i fill
> the
> components manualy with what has come from the database.
> 3. when the user clicks save, i call another stored procedure which
> updates
> the specified record
>
> This avoids me having to keep any record in "edit" mode at all, leaving
> other users able to browse and modify such records. To make it more
> effecient ud probaby only update the field that has been changed, but
> that's
> another story.
>
> Hope any of this is relevant...
>
> J
> ----- Original Message -----
> From: "Nesler, Thomas J" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Wednesday, April 26, 2006 7:15 PM
> Subject: RE: [delphi-en] Using the TTable Edit Error Event
>
>
>> Hi Bob!
>>
>> I am using NexusDb version 1.08 and it does give me an error when a
>> record is locked. Unfortunately it does not resolve the conflict by
>> preventing the second user from editing the record. Which means that
>> the first user can't exit the record and post because the second user
> is
>> still editing the record.
>>
>> I am guessing that this is a problem that is tied to the Blob Memo
> that
>> the user is trying to edit. Since Blob memos are handled differently
>> than regular records, I am thinking that is why I am getting these
> ugly
>> error messages.
>>
>> What do you suggest?
>>
>> Tom Nesler
>>
>>
>> -----Original Message-----
>> From: [email protected] [mailto:[EMAIL PROTECTED] On
>> Behalf Of [EMAIL PROTECTED]
>> Sent: Wednesday, April 26, 2006 11:00 AM
>> To: [email protected]
>> Subject: Re: [delphi-en] Using the TTable Edit Error Event
>>
>>
>> Hi Thomas,
>> as usual "it depends".
>> Which Database do you use? A "normal" SQL Client / Server RDB (as
>> Firebird or Interbase) is able to handle that automatically.
>> So, which Delphi version and which DB you are talking about.
>>
>> Have fun
>> Bob
>>
>>
>>> I am working on a multiuser application. One of my problems is
>> record
>>> locking, specifically when one user is editing a blob field and
>> another
>>> is editing the same record.
>>>
>>> I am guessing that I need to put some code in the Edit error
> event
>> but
>>> there is no example in the Delphi help file so I can only guess
>> how to
>>> use it correctly.
>>>
>>> Can some one give me an example on how to trap a record locking
>> error
>>> using this event? Also what do you recommend for help in
>> understanding
>>> the complexities of multiuser databases?
>>>
>>> Thanks in advance!
>>>
>>> Tom Nesler
>>> Live long!... Code Well!... and Prosper!... V
>>>
>>>
>>> [Non-text portions of this message have been removed]
>>>
>>>
>>>
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