created by https://github.com/tr3buchet/gister

map-unmapped.sql

create table customer (
  id integer primary key autoincrement,
  name text not null
);

create table cupon (
  id integer primary key autoincrement,
  code text not null
);

create table customer_cupon_map (
  customer_id integer not null,
  cupon_id integer not null,
  foreign key (customer_id) references customer(id),
  foreign key (cupon_id) references cupon(id),
  unique(customer_id,cupon_id)
);

insert into customer(name, id) values ('egon', 1001), ('dave', 2002), ('carol', 3003), ('bob', 4004), ('alice', 5005);
insert into cupon(code, id) values ('itsyourshow', 11), ('relayfm', 22), ('warmbo', 33), ('eatfresh', 44), ('morecodes', 55), ('bigweek', 66);

insert into customer_cupon_map(customer_id, cupon_id)
select customer.id, cupon.id from customer, cupon
 where customer.name = 'alice' and cupon.code = 'itsyourshow';

select * from customer_cupon_map;
select '
       -------
       ';

with
  rowed_customer(custrow, custname, custid) as (
    select (row_number() over (order by customer.name)), customer.name, customer.id
      from customer
     where not exists (select 1 from customer_cupon_map where customer_id = customer.id)
     order by customer.name
  ),
  rowed_cupon(cuprow, cupcode, cupid) as (
    select (row_number() over (order by cupon.code)), cupon.code, cupon.id
      from cupon
     where not exists (select 1 from customer_cupon_map where cupon_id = cupon.id)
     order by cupon.code
  )
  insert into customer_cupon_map
select custid, cupid from rowed_customer join rowed_cupon where custrow = cuprow;


select * from customer_cupon_map;

output.txt

5005|11

       -------
       
5005|11
4004|66
3003|44
2002|55
1001|22