How to use Rails 7.1 composite foreign keys along with Brick?

[lorint]

This question comes from a question raised on the Rails discussion board. Given tables created in Postgres with this code:

CREATE TABLE songs(
    "songId" INTEGER,
    "chartId" INTEGER,
    version INTEGER,
    name VARCHAR,
    PRIMARY KEY ("songId", "chartId", version)
);

CREATE TABLE scores(
    id SERIAL PRIMARY KEY,
    "musicId" INTEGER,
    level INTEGER,
    version INTEGER,
    instrument VARCHAR,
    FOREIGN KEY ("musicId", level, version) REFERENCES songs("songId", "chartId", version)
);

INSERT INTO songs ("songId", "chartId", version, name)
  VALUES (5, 3, 1, 'Requiem');
INSERT INTO songs ("songId", "chartId", version, name)
  VALUES (6, 3, 1, 'Take Five');
INSERT INTO songs ("songId", "chartId", version, name)
  VALUES (5, 3, 2, 'Requiem');

Your models can be created like this:

class Song < ApplicationRecord
  # Primary key: songId, chartId, version
  has_many :scores, query_constraints: ["musicId", "level", "version"]
end

class Score < ApplicationRecord
  belongs_to :songs, query_constraints: ["musicId", "level", "version"]
end

Here is a video walkthrough showing how easy it can be using Brick to arrive upon this result: https://github.com/lorint/brick/assets/5301131/92593ae7-75ce-4d7d-9f0a-df54ff2b0ec7

(not related is this other video about creating models for friend requests which I have linked here just as a placeholder so that Github will hold on to it.)