-- a foo table
create table foo (
	id	int not null primary key auto_increment,
	foo	varchar(255) not null
);

-- a bar table
create table bar (
	id	int not null primary key auto_increment,
	bar	varchar(255) not null
);

-- a linking table
create table foo_bar (
	foo_id  int not null references foo(id),
	bar_id  int not null references bar(id)
);

-- a naked qux table
create table qux (
	id	int not null primary key auto_increment,
	qux	varchar(255) not null
);