drop table alien cascade;
drop table assembly cascade;
drop table car cascade;
drop table dept cascade;
drop table donor cascade;
drop table emp cascade;
drop table gift cascade;
drop table item cascade;
drop table lineitem cascade;
drop table monarch cascade;
drop table nation cascade;
drop table person cascade;
drop table product cascade;
drop table qdel cascade;
drop table qdept cascade;
drop table qemp cascade;
drop table qitem cascade;
drop table qsale cascade;
drop table qspl cascade;
drop table sale cascade;
drop table shr cascade;
drop table stock cascade;
drop table year cascade;
drop table exped cascade;