execQueryWithParameter(db, "DELETE FROM EVENT_ROOM WHERE xid_conference = :xid_conference", params);
execQueryWithParameter(db, "DELETE FROM EVENT_PERSON WHERE xid_conference = :xid_conference", params);
execQueryWithParameter(db, "DELETE FROM EVENT WHERE xid_conference = :xid_conference", params);
execQueryWithParameter(db, "DELETE FROM EVENT_ROOM WHERE xid_conference = :xid_conference", params);
execQueryWithParameter(db, "DELETE FROM EVENT_PERSON WHERE xid_conference = :xid_conference", params);
execQueryWithParameter(db, "DELETE FROM EVENT WHERE xid_conference = :xid_conference", params);