Quick - debugging "Data expression error"

[Kogan, Arthur]

Hi Chris,

as you are probably aware, this error is caused by trying to "fit a
square block into a round hole" so to speak, ie trying to put a value
into a field which can not hold it. The only way to pick out where it is
occuring is by debugging (I always use "info" statements for this). 

Now here is something that might be usefull. I had a case with one
customer getting the same error and it was happening between the "let"
satements. What it was, was this: he had a "get file optional" statement
accessing a file using a field from another file. The linking field
although of the same name, was defined as char*8 in one file and char*10
in another. So, when the value was upto 8 characters, there was no error
and the link was made (assuming there was an appropriate match), but if
the value was 9 or 10 characters, they got the error. Because the get
was optional (it was a minor issue anyway if the matching record was
there or not), it did not really affect their logic, but the error was a
nuisance!

I have only mailed this to point out that this issue could occur in
places you would not normally expect (ie you would be looking at "let"
statements), so I hope it helps in your investigations.

Regards,


> Arthur Kogan   COGNOS Customer Support
> e-mail:  Arthur.Kogan@cognos.com
phone: 61-2-94376655     fax: 61-2-94381641

The difficult we do immediately,
the impossible takes a little longer.



> ----------
> From:
> Chris.Sharman@ccagroup.co.uk[SMTP:Chris.Sharman@ccagroup.co.uk]
> Sent:  Tuesday, February 17, 1998 3:13 AM
> To:  gfax%cognos-tsc@ccagroup.co.uk
> Cc:  powerh-l@lists.swau.edu; Chris.Sharman@ccagroup.co.uk
> Subject:  Quick - debugging "Data expression error"
> 
> We're using Alpha VMS 6.2, PH 7.10.F3
> 
> Some of our screens, particularly our purchase invoice screen, give
> "Data
> expression error". We can never see which calculation is in error;
> even in the
> debugger the message does not appear until the next screen prompt. We
> can't see
> anything wrong with the data (either input or written by the screen).
> 
> Users are (justifiably) made rather nervous by this.
> 
> Is there an easy way to pin down Quick errors and warnings ? Either
> via the
> debugger or some other way, such as a more refined error message or a
> line
> number or field name ?
> 
> Thanks, Chris
> ______________________________________________________________________
> Chris Sharman   Chris.Sharman@CCAgroup.co.uk
> CCA Stationery Ltd, Eastway, Fulwood, Preston, Lancashire, PR2 9WS.
>