[Lazarus] RE : RE : @DBLookupControls users: call for test

Luiz Americo Pereira Camara luizmed at oi.com.br
Mon Dec 12 19:29:18 CET 2011


On 12/12/2011 16:03, Ludo Brands wrote:
>> I also noted the different behavior and did not changed. In
>> my opinion
>> the LCL behavior is better since ListSource must be used only
>> as lookup
>> for the data to be displayed and it's cursor should not be
>> changed. It
>> must change only the field to what is linked
>>
> Well, if you use a listsource that is an active datasource for another
> control, I would expect the 2 to be in sync. If I want a listsource that is
> only a lookup, then I use a different (and probably smaller containing only
> 1 or 2 fields, filterd, etc) one. An expectation that is perhaps based on an
> habit created by Delphi but still...
>
>> In fact all db controls (not only lookup) linked to the same
>> field are
>> changed.
>>
> Linked to the datasource that is, not the ListSource.
>
>> Can you post a project example where this cause a problem?
>>
> Ex:Order processing, article detail window opened, customer wants XYZ but
> "the one with the round corners". Order taker enters XYZ in order screen and
> scrolls through the different values while looking at detail screen until he
> finds "round corners" or something similar.
> Ex:Order processing, same customer, 2 addresses, 2 ID's. Customer detail
> window used to check address, contact person or whatever.


Wat if i have one field point to a value in the listsource and another 
field pointing to another value?

What is the cursor position of the ListSource?

> The same can be done without ListSource cursor updates but not as efficient.
> It requires more user actions.
>

You are looking for a TDataset that implements Master/Detail 
relationship. AFAIK TDBF and TSqlite3Dataset implements that.

Luiz





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