I use a TIBODatabase inside a DLL, and it works the same way as the
TIBODatabase of the main application. When i create a query inside
the DLL, it automatically assumes the DLL TIBODatabase as it's
database.

The way i do this is passing the main TIBODatabase to the DLL as the
parameter of a procedure, and, inside this procedure:

DLLIBODatabase.SchemaCacheDir := MainIBODatabase.SchemaCacheDir;
DLLIBODatabase.dbHandleShared := MainIBODatabase.dbHandle;
DLLIBODatabase.IB_Session.DefaultConnection := DLLIBODatabase;

It's working without problems, and my employee who did this found
this information asking in this newsgroup. Unfortunatelly i'm not
having success to search the archives.

Recently Helen told me it's not the right way to do this. Could you
point me the right way?

Thanks.