Thank you Helen for the indication.

I've notice one thing in the export to DBF format :
Longint Field (of a firebird database) seems to be converted to float
field...
This may produce an error if there are values in the field.

(I've wrote a simple SQL instruction in the SQL property of the
IB_exportDialog :

Select * from my DATABASE...)

I'm using the 4.2Ie version of IBO...

Michel LE CLEZIO.