Subject RE: [IBO] Howto manually update control when detail dataset chang es
Author Norman Dunbar
Mirco wrote :

>> The question is: how do I know when the detail dataset requeries?

>> 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'.

Correct me if I'm wrong on this, but surely, when the master dataset
scrolls, the field linking the detail data set to the master must change, so
the detail query must therefore be re-queried ?

Example :

Customer and Invoices, Customer is master and Invoices the detail. They are
linked by Customer_number.
The master query, for sake of argument is 'select * from customer' and the
details is 'select * from invoice' - they are joined in the correct, which
is set to link them by customer_number. (MasterLink probably - I'm working
blind here :o) )

So, when the customer details are displayed, the invoice details are really
'select * from invoice where customer_number = :customer_number' and the
parameter is automagically filled in from the customer dataseet's current

When the customer dataset is scrolled, the customer_number (probably)
changes, so the detail is re-queried.

Hence, you would put your processing in the AfterScroll event as advised.



PS. Or have I missed the point (again) ?

Norman Dunbar
Database/Unix administrator
Lynx Financial Systems Ltd.
Tel: 0113 289 6265
Fax: 0113 289 3146

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