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SQLEXEC and Shared Connection Problems
Message
From
12/11/2004 04:16:17
 
 
To
11/11/2004 16:32:12
General information
Forum:
Visual FoxPro
Category:
Databases,Tables, Views, Indexing and SQL syntax
Environment versions
Visual FoxPro:
VFP 8
OS:
Windows XP SP1
Database:
MS SQL Server
Miscellaneous
Thread ID:
00960314
Message ID:
00960715
Views:
10
>Hi Fabio,
>
>The AllowSimultaneousFetch wasn't specifically designed to support asynchronous execution. It was designed to support simultaneous fetch using two or more SPT connection handles sharing the same ODBC connection, but with synchronous execution. Primarily, with remote views and CursorAdapter objects.
>
>The support for simultaneous fetch depends on the driver's capabilities to perform it. Obviously, ODBC driver for Sql Server is not capable to do this when asynchronous execution is in effect. Normally, it would give you an error as soon as you try to execute something without finishing/canceling the async execution, but when you try to force it with AllowSimultaneousFetch = .T. the driver goes into wait state, I assume it is waiting for the first execution to complete its work.
>
>Thanks,
>Aleksey.
>

This I had understood, and I hope it that SQL 2005 (MARS behaviour) can fix this.

But!, you can to explain we as this behavior in synchronous modality can be useful ?
With synchronous execution VFP it downloads all the cursor before returning the execution, and therefore I do not see the simultaneous execution.

Or, VFPT have developed an inner management that manages the shared connection and therefore it interleaved out the several QDBC SQLGetData(HSTMT) so as to to download more STMTs?

This manager control the SPT SQLEXEC() execution or not?
I think no.

On the web don't exists ONE, I say ONE, example where
AllowSimultaneousFetch it is used.

You can arrange this lack today ?

Thanks.
Fabio
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