OLE Automation, "Invalid Variant Conversion"

Bryce Fischer

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

OLE Automation, "Invalid Variant Conversion"

Hope someone can help me with this problem. I am using OLE Automation to
control an Access Database. I am trying to get data from an Access Table.
The Field in question is empty. When it tries to execute the statement, I
get an "Invalid Variant Conversion". I am using Delphi 2.01, with Access 7.

Code:
procedure Convert;
begin
...
// Assume all OLE objects have been created.
// Database is the currently open access database

RecordSet := Database.OpenRecordSet('select * from OFFICE');

Fax2 := RecordSet.Fields['Fax'].Value; <== Invalid Variant
Conversion
end;

If I put data in the field, doesn't complain at all. I can assign values to
the Field using:
RecordSet.Fields['Fax'].Value := Fax2; // Fax2 has been initialized.

I have tried typcasting, checking to see if it is equal to '', ' ', and
NULL.. None seem to work.

Any insights or help would greatly be appreciated.

thanks
Bryce
p.s. Please cc a reply to vbfisc...@tasc.com

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Re:OLE Automation, "Invalid Variant Conversion"

Bryce Fische

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Re:OLE Automation, "Invalid Variant Conversion"

Never mind! I must not have checked for NULL. I was trying to prove it to a
co-worker, and it worked when I tested for NULL

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Re:OLE Automation, "Invalid Variant Conversion"

Marcel J Ma

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Re:OLE Automation, "Invalid Variant Conversion"

On 15 May 1997 20:05:37 GMT, "Bryce Fischer" <*fisch...@ix.netcom.com>
wrote:

Quote

>Hope someone can help me with this problem. I am using OLE Automation to
>control an Access Database. I am trying to get data from an Access Table.
>The Field in question is empty. When it tries to execute the statement, I
>get an "Invalid Variant Conversion". I am using Delphi 2.01, with Access 7.

>Code:
>procedure Convert;
>begin
> ...
> // Assume all OLE objects have been created.
> // Database is the currently open access database

> RecordSet := Database.OpenRecordSet('select * from OFFICE');

> Fax2 := RecordSet.Fields['Fax'].Value; <== Invalid Variant
>Conversion
>end;

>If I put data in the field, doesn't complain at all. I can assign values to
>the Field using:
> RecordSet.Fields['Fax'].Value := Fax2; // Fax2 has been initialized.

>I have tried typcasting, checking to see if it is equal to '', ' ', and
>NULL.. None seem to work.

You might try testing for UnAssigned, which is supposed to be
different from Null

Good luck

Marcel Mar
Amsterdam, The Netherlands

e-mail: *remove_this*mjm...@inter.nl.net*remove_this*

Bruce C. Goldstei

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Re:OLE Automation, "Invalid Variant Conversion"

Actually, I believe all you have to use is the
VarAsType(<variable>,varOleString) or whatever you need to do...

Bruce

Quote

Marcel J Mar wrote:

> On 15 May 1997 20:05:37 GMT, "Bryce Fischer" <*fisch...@ix.netcom.com>
> wrote:

> >Hope someone can help me with this problem. I am using OLE Automation to
> >control an Access Database. I am trying to get data from an Access Table.
> >The Field in question is empty. When it tries to execute the statement, I
> >get an "Invalid Variant Conversion". I am using Delphi 2.01, with Access 7.

> >Code:
> >procedure Convert;
> >begin
> > ...
> > // Assume all OLE objects have been created.
> > // Database is the currently open access database

> > RecordSet := Database.OpenRecordSet('select * from OFFICE');

> > Fax2 := RecordSet.Fields['Fax'].Value; <== Invalid Variant
> >Conversion
> >end;

> >If I put data in the field, doesn't complain at all. I can assign values to
> >the Field using:
> > RecordSet.Fields['Fax'].Value := Fax2; // Fax2 has been initialized.

> >I have tried typcasting, checking to see if it is equal to '', ' ', and
> >NULL.. None seem to work.

> You might try testing for UnAssigned, which is supposed to be
> different from Null

> Good luck

> Marcel Mar
> Amsterdam, The Netherlands

> e-mail: *remove_this*mjm...@inter.nl.net*remove_this*

Other Threads

1. "Invalid variant type conversion"

2. "Invalid variant type conversion"

3. "Invalid variant conversion" error

4. TBetterADODataSet and error "Invalid variant operation"

5. "invalid varient type conversion"

6. Running Another Application "NOT OLE Automation"

7. Ole Automation + "Castastrophic Failure"

8. Interface flag - "Ole automation".

9. The keys "-"/"+"/"*"

10. "variant method calls not supported"