Subject AW: [IBO] Problems with TwwIBOQuery and Params (Invalid Variant Operation - when opening detailquery)
Author Christian Kaas
I've looked into the source of TwwIBOQuery - it is a descendant of
TIBODataset !
So the problem is in IBO.
Can just one of you guys dig into it? If necessary i'll provide you with
an example (including gdb file).



--
Christian Kaas mailto:christian@...
Client/Server/Internet/Multitier development
http://www.ckaas.de

> -----Ursprungliche Nachricht-----
> Von: Geoff Worboys [mailto:geoff@...]
> Gesendet: Samstag, 30. Dezember 2000 02:45
> An: IBObjects@egroups.com
> Betreff: Re: [IBO] Problems with TwwIBOQuery and Params
> (Invalid Variant
> Operation - when opening detailquery)
>
>
> Christian,
>
> > I have to add, the value of the masterkey is 99990000000001!
> > If the keyfield contains less digits it seems to work!
> <...>
> > > try to open the detail or master i get an "Invalid variant
> > > Operation" message/exception.
>
> The Variant datatype does not support INT64 (at least not directly).
> I have come across this problem with other third party products that
> expect to be able to store a field value in a variant.
>
> TDataset and IBO force the storage of int64 into variant using a
> special type indicator, but this vartype is not implemented for all
> variant functions, sometimes leading to invalid operation errors.
>
> In your instance you may be able to resolve the problem by splitting
> your key values into multiple fields (IB and IBO supports compound
> keys).
>
>
> I would expect that the problem comes from the InfoPower code (since
> IBO does not usually need to use variant for its manipulations). Do
> you have the source for InfoPower, can you at least provide a
> callstack for the problem. Perhaps someone else with InfoPower and
> IBO full source can detect where the problem is coming from and a
> workaround can be implemented.
>
> One workaround may be to provide have int64 use string values with
> AsVariant functions. But I have not tried this to see what happens.
>
>
> Geoff Worboys
> Telesis Computing
>
>
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