Problem reading information from Query

[checco]

Hello to All,
I'm occurring in one problem when I start to collect information from a query when the wanted filed it's empty.

Here after a part of my fault code:
...
AnsiString stringa;
...
stringa+=QAll->FieldValues["cdPartySubscriber"];
stringa+=",";
...
In this case if the field "cdPartySubscriber" is empty I receive the error "...my project raise an excepption class EVarianError with message "Invalid variant Type conversion".....

I want to do something like this:
...
if(QAll->FieldValues["cdPArtySubscriber"]!=NULL)
stringa+=QAll->FieldValues["cdPartySubscriber"];
stringa+=",";
...
but in this case the if is always ignored (the expression results always true) and I receive the same error message.

Just for infomation the db is oracle.

Some one can help me ?


Thanks in advance for any answer
Checco

 

[2ffat]

I'm doing this from memory but it should point you to the right spot.

AnsiString stringa;
...
try
{
    stringa+=QAll->FieldValues["cdPartySubscriber"];
}
catch (&EVarianError)
{
    // Do something or nothing
}
stringa+=",";

What I don't remember is the exact format of the catch for this type of exceptions.

James P. Cottingham
-----------------------------------------
[sup]To determine how long it will take to write and debug a program, take your best estimate, multiply that by two, add one, and convert to the next higher units.[/sup]

 

[checco]

Hi 2ffat,
first of all thanks for your help that is always very usefull.
With your suggestion I'm able to manage both case, but each time that I occour in the exception I receive the error message box.
Is it possible to "hide" that message in order to let my program continue ?

P.S. I've used this format for catch the exception:
catch (Exception &EVarianError)
May-be it is not correct ?

Thanks again for your usefull help,
Checco

 

[checco]

Hi again to all,
please do not take care about my last reply... I'll take a crab ;-)))))

Sorry but I'm not so skilled.

2ffat Thank again you suggestion solve my problem in the best way.

Bye,
Checco

 

[Pantaz]

Your "if" statement may be failing because a field can be empty without being "NULL".
You need to also check for an empty string ("").