At 11:28 AM 24/02/2004 +0100, you wrote:

>At 09:56 Tuesday, 24.02.2004 +0000, kiki446 wrote:
> >Try to compile it on D6 and choose ID_Lookup from ComboBox on right
> >side. Maybe it's something with D7 ?
>
>I have tried your first and second example here: D5, IBObjects 4.3 Aa,
>WinXP Pro, Firebird1.5.
>With both test apps I got the error you described.

I tried the second example with D5 and all the above (except Win2K) and
also got exceptions (plural) eInvalidVariant. I tried a few things such as:

removing all the TField descendants and using FieldByName (both .Value and
various casting methods); changed the creation order of the objects on the
datamodule; changed the Open calls so that the Master opened before the
Detail (since the detail query is dependent on a parameter from the
master)...all to no avail.

Tracing as I go, the exception that finally causes the whole thing to croak
is at line 3799 of InternalSetFieldData in IBODataset.pas. At that point,
the routine seems to be trying to cast the variant values to floats (though
I've probably missed something earlier in the logic - it's a huge function.

Sorry, but I've already spent too many hours on this. I have to leave it
now and catch up on what I should have been doing. :-| Hope someone
cracks it soon.

Helen