Subject Re: [IBO] Suggestions Please
Author Ramil
Hi Matt,
29.04.2005 4:09, you wrote:

> I have an application that needs to prevent a user from performing an
> action until all other users are out of a specific table. I can think
> of several ways to accomplish this but not of which is resistant to
> abnormal database disconnects. I would appreciate any suggestions.

> Example:

> User A, B, C are entering payroll numbers for the month.

> User D processes those number, but as a failsafe the system needs to
> make sure that users A, B, C are not still entering numbers into the
> table that User D is going to process. I don't want to prevent users
> A, B, C from entering number but I want to tell user D that they are
> still doing so.

> Thanks,

> Matt

If you decide use status table and some user
has abnormal database disconnect. You can have
frozen state. User for ex. "B" turn on entering
mode and couldn't turn it off.

You can use events mechanism in your applications.
User D run stored procedure what contain
POST_EVENT 'EVERYBODYENTERING';
And waiting for few seconds.

Users A, B, C registered this event name in own applications
can recieve it. And if anybody entering payroll numbers, then
he send reply by stored procedure what contain
POST_EVENT 'YESENTERING';
User D catch this event and know - numbers still entering.

Ramil