notworking.graphql

mutation {
  updateQuote(
    input: {
      patch: {
        quoteDaysUsingId: {
          updateById: {
            patch: { propertyToPropertyId: { connectById: { id: 1 } } }
            id: 1
          }
        }
      }
      id: 1
    }
  ) {
    quote {
      id
      quoteDays {
        nodes {
          id
          property {
            value
          }
        }
      }
    }
  }
}

schema.sql

create table quote
(
  id int not null primary key
);

create table property
(
  id int not null primary key,
  value text
);

create table quote_day
(
  id int not null primary key,
  quote_id int not null references quote (id),
  property_id int not null references property (id)
);

insert into property
values (1, 'Property 1');

insert into property
values (2, 'Property 2');

insert into quote
values (1);

insert into quote_day
values (1, 1, 1);

working.graphql

mutation {
  updateQuoteDay(input: { id: 1, patch: { propertyId: 1 } }) {
    quoteDay {
      property {
        value
      }
    }
  }
}