create table R(A INTEGER);
create table S(A INTEGER);

insert into R values('1');
insert into R values('1');
insert into R values('2');
insert into R values('2');
insert into R values('3');

insert into S values('1');
insert into S values('2');
insert into S values('2');
insert into S values('2');
insert into S values('4');

/********************** Set Operations **********************/

/* EXCEPT removes duplicates */
/*
SELECT * FROM R
EXCEPT
SELECT * FROM S;
*/

/* INTERSECT removes duplicates */
/*
SELECT * FROM R
INTERSECT
SELECT * FROM S;
*/

/* UNION ALL does not remove duplicates */
/*
SELECT * FROM R
UNION ALL
SELECT * FROM S;
*/

/* MINUS/EXCEPT ALL does not remove duplicates.
  not implemented in SQLite */
/*
SELECT * FROM R
EXCEPT ALL
SELECT * FROM S;
*/