-------------------------------------------------------------
-- cs3200 Database design
-- v180121
-------------------------------------------------------------



-------------------------
-- Drop tables if they already exist
-------------------------

DO $$
BEGIN
IF EXISTS (SELECT * FROM information_schema.tables 
	WHERE table_name = 'r') THEN
   DROP Table R;
END IF;
IF EXISTS (SELECT * FROM information_schema.tables 
	WHERE table_name = 's') THEN
   DROP Table S;
END IF;
IF EXISTS (SELECT * FROM information_schema.tables 
	WHERE table_name = 't') THEN
   DROP Table T;
END IF;
IF EXISTS (SELECT * FROM information_schema.tables 
	WHERE table_name = 't2') THEN
   DROP Table T2;
END IF;
IF EXISTS (SELECT * FROM information_schema.tables 
	WHERE table_name = 'U') THEN
   DROP Table U;
END IF;




-------------------------
-- Create tables
-------------------------

create table R (a int PRIMARY KEY); 
create table S (a int PRIMARY KEY); 
create table T (a int PRIMARY KEY); 
create table T2 (a int PRIMARY KEY); 
create table U (a int PRIMARY KEY); 


---------------------------
-- Populate the tables
---------------------------

insert into R values (1);
insert into R values (2);
insert into S values (1);
insert into T values (2);
insert into U values (2);
insert into U values (3);
insert into U values (4);
END $$