Blank Charts on Reports

[AlCamp]

Well folks, I posted this question several days ago, but still have not
found a solution... I've built many charts in the past, and although I've
pulled my hair out a few times, I was always able to get the job done.

In Access97 I have a XY Scatter chart in the Report Footer "linked" to
the report (Parent/Child) by RollNo.
When I use the Parent/Child Link wizard, I get "Can't build a link between
unbound forms", but I think that's a known bug, so I just enter
RollNo/RollNo.

The problem...
When I first Preview the report via the "calling form", the chart comes
up blank. (I can see the title, but no chart or data)
If I close the report and re-preview the report via the calling form
again ... still the same... the chart is blank.
I have a Refresh when I call the report, and per Fred G., I have a
Chart.Requery in the ReportFooter Format event.

BUT, if I go into Design mode for the report, and immediatelt preview it
again, the chart
displays perfectly!

If I don't use a Parent/Child link at all, the graph displays every
time... but it displays ALL error data, not just the specific RollNo data.
That makes sense...
So... I put a criteria in the crosstab query behind the Graph of
"=Forms!frmInspectionDefects!RollNo" ( the same value that filters the main
report successfully), and the chart fails with "The Microsoft Jet database
engine does not recognize <name> as a valid field name or expression. (Error
3070)".
So... then I tried using the RollNo on the report itself with... "=
Reports!rptGraphedDefects!RollNo" and get the same error!

Why won't the graph crosstab query recognize these legitimate external
values? A timing problem between report sections perhaps? But why not the
open form?

Why does the Parent/Child RollNo link (when used) cause the graph to come
up blank on Preview from my calling form, but work fine in preview from
Design mode?

Don't know what else to try, and I've been at this for days. Any
suggestions would be appreciated. I'm stumped right now...

Thanks,
Al Camp

 

[Duane Hookom]

Any time you use a dynamice criteria in a crosstab, you must declare the
data types of your parameters. Select Query->Parameters and enter the exact
parameter and select its data type.

Also ACGSofts' web site has some good trouble-shooting hints on
graphs.http://ourworld.compuserve.com/homepages/attac-cg/

 

[AlCamp]

Duane,
Thanks a lot... I'll try that out, check out the link, and get back to
you. It might take a bit, but I'll respond back.
Al Camp

 

[AlCamp]

Duane,
Wicked good!! Declaring the parameter seems to do the trick.
I can't tell you how much time I spent on that problem... thanks very
much.
What a resource these newsgroups are!

Again, thanks a lot...
Al Camp