How do I prevent my ASP pages from waiting for backend activity?
If you are trying to run an executable or other backend process, see Adrian Forbes' article:
Executing long-running tasks from ASP
If you are trying to run long-running database tasks, then the following is designed for a very specific scenario. Your ASP page should:
So, let's say we have a database, called scratch:
And we have a table, called TimeRecord:
And a stored procedure that inserts, after an odd five-second delay, the current timestamp.
Now, traditionally, in ASP we would call this procedure as follows:
And sure enough, we would see that it takes more than five seconds for the browser to process the results.
One approach would be to use the asynchronous flag (adAsyncExecute — &H00000010, or 16):
This approach can be used in both Access and SQL Server, though we have not tested it extensively in Access.
Note that, in this case, you must not close the connection object or set it to nothing, or else you receive this error:
Another approach might be to create a job in SQL Server (for obvious reasons, this approach is not valid for Access). Note that this technique requires elevated privileges...
Here is the code for the job:
Now, you can have a stored procedure that calls this job (this will cause the call to operate asynchronously):
The procedure is a little longer than it should be, because we first check that the job isn't already running, in order to avoid an ugly error (we'll handle this in ASP below).
One word of warning: errors get swallowed up by the provider when using asynchronous methods, so you'll want to employ this method carefully.
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