drop table city;
drop table boundary;
drop table political_unit;
create table political_unit (
	unitname						 	varchar(30) not null,
	unitcode						 	char(2),
	unitpop 							decimal(6,2),
	PRIMARY KEY(unitcode));
create table boundary (
	boundid 							INTEGER,
	boundpath						 	polygon NOT NULL,
	unitcode						 	char(2),
	PRIMARY KEY(boundid),
	constraint fk_boundary_polunit FOREIGN KEY(unitcode)
		REFERENCES political_unit(unitname)) TYPE MYISAM;
create table city (
	cityname						 	varchar(30),
	cityloc						 	point not null,
	unitcode						 	char(2),
	PRIMARY KEY(unitcode,cityname),
	constraint fk_city_polunit FOREIGN KEY(unitcode) 
		REFERENCES political_unit(unitname)) TYPE MYISAM;