drop table pt;
drop table ingredient;
drop table recipe;
drop table connection;
drop table hut;
drop table store;
drop table guard;
drop table  confiscates;
drop table  recipe_ing;
drop table  delivery;
drop table  delivery_ing;
drop sequence delivery_did_seq;

create table pt (
  id int primary key
);

create table ingredient (
  name varchar(20) primary key
);

create table recipe (
  name varchar(20) primary key
);

create table connection (
  p1 int references pt not null,  
  p2 int references pt not null
);

create table hut (
  owner  varchar(20) primary key,
  pid    int references pt not null
);

create table store (
  name  varchar(20) primary key,
  pid   int references pt not null
);

create table guard (
  name  varchar(20) primary key,
  pid   int references pt not null
);

create table confiscates (
  guard       varchar(20) references guard not null,
  ingredient  varchar(20) references ingredient not null
);

create table recipe_ing (
  recipe      varchar(20) references recipe not null,
  ingredient  varchar(20) references ingredient not null
);

create table delivery (
  did       serial primary key,
  sender    varchar(20) references store not null,
  receiver  varchar(20) references hut not null,
  path      int[] 
);

create table delivery_ing (
  did         int references delivery,
  ingredient  varchar(20) references ingredient
);