use Red; unit model Red::Migration::Table is table<red_migration_table>; has UInt $!id is serial; has Str $.name is column is required; has Version $.version is column is required; has Instant $.created-at is column = now; has UInt $.migration-id is referencing{ :column<id>, :model<Red::Migration::Migration>}; has $.migration is relationship( { .migration-id }, :model<Red::Migration::Migration> ); has @.columns is relationship( { .table-id }, :model<Red::Migration::Column>); ::?CLASS.^add-unique-constraint: { .name, .version };