>It's possible insert a record in any position of the DBGRID (except
>at the end) and that the same DBGrid position is conserved in the
>physical table.

Hmm, how to explain this?

A desktop database is like a bookshelf. You place books at set places and
they stay where they are. Paradox and Access are such desktop databases,
but Interbase isn't.

A client/server database is more like your laundry basket. You just throw
everything in, and don't care about the physical position. It would be
crazy to put your dirty clothes nicely ordered withing the basket - you
sort them when you take them out of there. And Interbase is such a
client/server database.

What you have to do is to create indexes and include a sort order for your
queries. To insert something at a specific place, you just use a value for
that indexed column which is between the preceding and succeeding record.
"Just" may be the wrong word to use if you want to do this for an entire
table. Supposing there is no gap between two records, you may have to
modify all the succeeding records which may cause you some trouble in a
multiuser environment.

The best advice I can give you, is to stop thinking in terms of tables and
start thinking sets of records. If not, you'll never appreciate
client/server databases.

Good luck with your learning of client/server programming,
Set