FOREIGN KEY(xid_person) REFERENCES PERSON(id))");
query.exec("CREATE TABLE EVENT_ROOM ( \
xid_conference INTEGER NOT NULL , \
xid_event INTEGER NOT NULL , \
xid_room INTEGER NOT NULL, \
FOREIGN KEY(xid_person) REFERENCES PERSON(id))");
query.exec("CREATE TABLE EVENT_ROOM ( \
xid_conference INTEGER NOT NULL , \
xid_event INTEGER NOT NULL , \
xid_room INTEGER NOT NULL, \