Hi,

|know in the query result than myfield is of type D_Currency.
|For now i use the SQLDA.SQLType and SqlScale to know if it's NUMERIC(15,5)
field or not ...

you could query system tables:

select RDB$FIELD_SOURCE
from RDB$RELATION_FIELDS
where RDB$RELATION_NAME='YOUR_TABLE_NAME'
and RDB$FIELD_NAME='YOUR_FIELD_NAME';


Regards,
Anderson