At 01:18 PM 18/11/2004 +0100, you wrote:

>Helen Borrie wrote:
>[cut]
>Thanx for your exaustive answer.
>
> >>Links in TIBO_Query.KeyDescLinks are used when... with this syntax...
> >>
> >>
> >Not available to TIBOQuery. It's used as part of a linking for embedding
> >TIB_LookupCombo into a TIB_Grid.
> >
> >
>Only for grids? So, If I've a grid for select and a form for editing
>with some combolookup I'm not need KeyDescLinks?
>[cut]

The TIB_Grid and other native IBO controls can't be used with the TIBOQuery
and other TDataset-compatible components.

> >See also the examples in the Samples directory of your IBO installation.
> >
>Another question.
>There is particular reason for this syntax
>
>SELECT
> ID
> , TESTO
> , DATA
> , ID_AUTORE
> , (SELECT DESCRIZIONE FROM AUTORI
> WHERE ID=B.ID_AUTORE) AUTORE
>FROM BARZE B
>
>insted of (IMHO more cleaner )
>
>SELECT
> A.ID ID
> , TESTO
> , DATA
> , ID_AUTORE
> , DESCRIZIONE
>FROM
>BARZE B
>join
>AUTORI A
>on B.ID_AUTORE=A.ID
>
>I've seen this syntax in many examples...
>
>There is a reason to use 1st instead of 2nd ?

They are not the same. In the first, you will get all of the rows from
BARZE that are found by the WHERE clause; in the second, you will get all
of the rows in the table, but only those rows where a match is found for
the join.

The first query is equivalent to a left outer join between BARZE and AUTORI.

SQL questions should be posted in Firebird-support, by the way.

Helen