This method closes a connection. If the connection is already closed, it doesn't do anything. The TPDO will call this method before its destruction, so it's not necessary to explicitly call in that case.
procedure dbtest; var db: TPDO; begin db := TPDO.create; if (db.connect('mysql-4.0','10.0.0.152:3306','electronic_catalog','testuser','testpasswd')) then writeln ('connection succeeded.') else writeln ('connection failed.'); db.disconnect; db.free; end;