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ADO problems with VFP tables
Message
Information générale
Forum:
Visual FoxPro
Catégorie:
Client/serveur
Divers
Thread ID:
00229306
Message ID:
00229320
Vues:
19
As a overall rule, the OLE-DB provider determines what ADO can/cannot do. In this case, you need to use the OLE-DB Provider for ODBC.

Let me address your points below 1 by 1


>a) The MaxRecs property does not work. ADO ignores it when you wish to return only a few records in your cursor. It always returns all that match your SQL statement.
>

Did you use a server-side cursor here (cursorlocation=2). I think you will find different results if you set the cursor location to 3, client-side.

>b) The RowCount property always returns -1.

My guess is that you have created a forward-only, server-side cursor. You want a static (cursortype=3) cursor that resides on the client.

>c) It seems to lock the whole table and releases it only when you are done.

Do you have the exclusive checkbox checked in the ODBC connection manager for the DSN you are using???

>d) You cannot open the tables as Dynamic.

I believe this is a limitation of the OLE-DB Provider for ODBC. Access does'nt support this type either. Your cursor might be set as a keyset cursor.

>e) It is slow in selecting and adding records to large tables (Over 20,000 records)
>

ADO is a client/server technology. I have no doubts that fetching 20,000 records is a bit slow. For those type of operations, whatever they may be, you probably want to resort to using server-side components to work with the data.

>
>I also used it with Pervasive (Btrieve) database and I experienced the same problems. To me this means that MS again is not interested in supporting this thing for all its products or anyone elses. I guess ADO only works properly with SQL Server.
>

Not true. In case you did not know it, ADOx, the extension for DDL and security are designed to work with Access, not SQL-Server. Of course SQL-Server is going to get an OLE-DB Provider. The hope is VFP is going to get one as well. I for one have been beating the drum for it.

>Has anyone else had other problems when using ADO and VFP tables? 1

In limited situations, it works fine. I suspect that part of the issue here is more about configuration, and less about ADO. Why don't you post something about the app you are building and why you are using ADO.
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