CD sample

lib/Track.pm6

use Red;

model CD { ... }
model Artist { ... }

model Track {
   has Uint    $.id       is column{ :id, :!nullable };
   has Uint    $.cd-id    is referencing{ CD.id };
   has Str     $.title    is column;
   has CD      $.cd       = .^relates: { .id == $!cd-id };
   has Artist  $.artist   = .^relates: { .id == CD.artist-id AND CD.id == $!cd-id };
}

lib/CD.pm6

use Red;
use Track;

model Artist { ... }

model CD {
   has UInt             $.id          is column{ :id, :!nullable };
   has UInt             $!artist-id   is referencing{ Artist.id };
   has Str              $.title       is column;
   has UInt             $.year        is column;
   has Artist           $.artist      = .^relates: { .id == $!artist-id };
   has Track::ResultSeq $.tracks      = .^relates: { .cd-id == $!id };
}

lib/Artist.pm6

use Red;
use CD;

model Artist {
   has UInt          $.id    is column{ :id, :!nullable };
   has Str           $.name  is column{ :unique, :!nullable };
   has CD::ResultSeq $.cds   = .^relates: { .artist-id == $!id };
}