
-- mapping employee subclass hierarchy

create table Employees (
	empID integer primary key,
	name  text not null,
	address text
);

create table Permanents (
	empID integer references Employees(empID),
	salary float not null,
	primary key (empID)
);

create table Casuals (
	empID integer references Employees(empID),
	pay_rate float not null,
	primary key (empID)
);
