Thank you Helen and Lester

Just to make sure the problem is properly understood by everyone
(else), I will try to describe once again. I am sorry to insist on
this a bit, but my feeling is still that I either did not understand
the data driven part or there is something missing in IBO.

I do have a working master-detail relationship in my application. For
example, the master query is a list of all customers and the detail
is a list of orders for each customer.

A simple task is to simply display the detail set in the IBO grid, so
there is one row for each order and one column for each field. This
works fine and is well understood and documented.

What I want to do now is to display the detail dataset in a different
form - no matter what exactly - say a crosstab.

| Article1 | Article2 | Article3 |
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Month1 | count | | |
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Month2 | | | |
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Another example would be to make a chart from the data in the detail
dataset.
I know, there is no SQL query that would give me the results in a way
so I can just put them in a grid or chart control.
I know, I have to write some piece of code to iterate through the
whole detail dataset and put it into visualization.
This is works fine and is well understood.

My key issue is now: when do I have to call this code to update the
visualization? Answer: each time the detail dataset does a requery.
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The question is: how do I know when the detail dataset requeries?
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There is a straight-forward answer to this, which I heard several
times: do your update whenever the *master* datasource changes the
row.
As I said, this seems wrong to me. No, rather ineffective. It works,
yes, but you miss the point that
'master dataset scroll' is not equal to 'detail dataset requery'.
Scrolling the master dataset is *one* event to trigger a requery.
There are others.

I am wondering how TIB_Grid does it. It updates whenever the query it
is attached to requeries and doesn't know anything about other master
data sources.
So what is that event that makes the grid refresh all its rows and
that I would like to hook into to do the same with my special
visualization?

Sorry again to insist on this a bit and thank you for the support

Mirco