`pluck` causes an error
```
ERROR:  for SELECT DISTINCT, ORDER BY expressions must appear in select list
LINE 1: ... 236, 70, 15, 72, 6, 2, 21, 407, 401, 5) ORDER BY puppetclas...
                                                             ^
: SELECT DISTINCT puppetclasses.id FROM "puppetclasses" INNER JOIN "environment_classes" ON "puppetclasses"."id" = "environment_classes"."puppetclass_id" WHERE "environment_classes"."environment_id" = 1 AND "puppetclasses"."id" IN (54, 229, 236, 70, 15, 72, 6, 2, 21, 407, 401, 5) ORDER BY puppetclasses.name
```