Subject Re: iboTDataset
Author gerrwes
--- In, Helen Borrie <helebor@...> wrote:
> At 04:51 AM 13/03/2006, you wrote:
> >Hello Everyone,
> >
> >I need something very simple but I can't get it right. I've learned
> >not to fight something too long before asking when there are always
> >people willing and able to help.
> >
> >All I want to do is be able to edit a Firebird table with Almediadev's
> >BusinessSkinForm DB controls wich are TDataset descendants. When using
> >a TIBOTable as dataset I can edit just fine but I can't order the
> >records they way I want. When I use a TIBOQuery component I can
> >obviously sort but I can't edit ­ by navigator bar's editing buttons
> >remain greyed.
> >
> >First prize would be to skin the TIB_XXX editing controls but I'm not
> >an artist neither do I have time to create skins. Maybe somebody has
> >done so?
> >
> >Any help will be appreciated.
> The problem here appears to be that you are not
> providing a "live" dataset to your control.
> To be "editable", any dataset must "live". By
> nature, there is no such thing as "a live
> dataset" over a client/server database. Dataset
> objects do stuff under the hood to translate
> edit/insert/delete requests on a dataset row into
> DML statements that it constructs and sends over
> the wire when the application "posts" an e/i/d request.
> In order for a dataset to behave as though it
> were "live", it has to have two essential things:
> 1) Valid KeyLinks that uniquely identify the rows in the dataset
> 2) One DML statement to realise the dataset's
> insert/edit/delete requests as DML statements at Post time.
> What *you* have to do depends on the query.
> -- The simple case is a dataset that is the
> output of a simple SELECT on one table. For this
> case, you need the primary key of the table to be
> in the set and you set KeyLinksAutodefine
> true. The dataset will then take care of setting
> the KeyLinks itself. To make the dataset live,
> set the RequestLive property true. (By default,
> it is false.) The dataset then has everything it
> needs to construct parameterised DML statements
> for the InsertSQL, EditSQL and DeleteSQL properties.
> -- The less simple case is a dataset that is the
> output of joins or of a selectable stored
> procedure. In this case, you have to have at
> least the primary keys of each joined table in
> the KeyLinks that you want to be updatable. And
> you need to design the parameterised InsertSQL,
> EditSQL and DeleteSQL statements
> yourself. (RequestLive then becomes irrelevant.)
> And the other thing to know when using IBO is
> that the IBO components don't open automagically
> by default as the VCL components do. You have to
> open them in code. This goes for tiboconnection
> (tibodatabase) as well as your statement objects
> (tibotable and tiboquery). This is "by design",
> since opening an application with umpteen open
> datasets consumes a lot of wire
> capacity. Client/server workflow needs to be
> designed to respond to the needs and
> environmental conditions of users, not programmer convenience.
> If you want the VCL TDataset behaviour, of
> opening everything by default (not recommended,
> except for design-time convenience), you can set
> the StoreActive property of the IB_Session true.
> Helen


Thank you Helen for a very complete answer and the solution to my problem.