what is "Concurrency violation" ?

[yoramo]

Hello



Again a novice question (sorry). I have a row that any change to it
causes a error:

{"Concurrency violation: the UpdateCommand affected 0 records." }



I'm using MS-Access as the database.



I have read the help but there is no concurrency that I know. Any other row
that I update works fine only this specific row fails.



Any suggestion will be appertained.

Yoramo

 

[Hermit Dave]

Hey Yoramo,

This might be of your interest. Have a look
http://www.dotnet247.com/247reference/msgs/29/145707.aspx

Regards,
Hermit Dave

 

[Miha Markic]

Hi yoramo,

You might also read chapter

Concurrency Control in ADO.NET
in .net help files.

 

[Scott M.]

Concurrency is when 2 actions that conflict with each other are being
attempted.

Image you and I are both acessing a web page that lets us see and edit
employees. Now remember, in .NET we work with disconnected data, so the
data you will work with is a COPY of the original data and the same goes for
me.

If you begin to edit the record for "John Smith" (say, give him a raise) and
I delete the "John Smith" record completely (fired him), then what will
happen if I update the master (original) data with my copy BEFORE you do?

When you attempt to send your copy of the data back up to merge with the
original, you'll be trying to place the UPDATED "John Smith" record into a
table where no such record exists --- CONCURRENCY VIOLATION!

Scott M.