Trouble with datomic transaction fns

datomic-txn-fns.clj

(deftxnfn increase-book-quality
  [db eid attr quality]
  (do
    (assert (= :book/quality attr))
    (if (q '[:find ?eid .
             :in $ ?ords ?eid ?quality'
             :where
             [?eid :book/quality ?quality-eid]
             [?quality-eid :db/ident ?quality]
             [(get ?ords ?quality' -1) ?ord']
             [(get ?ords ?quality -1) ?ord]
             [(> ?ord' ?ord)]]
           db
           {:BookQuality/Poor 0
            :BookQuality/Good 1
            :BookQuality/Excellent 2}
           eid quality)
      [[:db/add eid :book/quality quality]]
      [])))

(defn increase-book-quality-txns
  [db eid quality]
  (if (q '[:find ?eid .
           :in $ ?ords ?eid ?quality'
           :where
           [?eid :book/quality ?quality-eid]
           [?quality-eid :db/ident ?quality]
           [(get ?ords ?quality' -1) ?ord']
           [(get ?ords ?quality -1) ?ord]
           [(> ?ord' ?ord)]]
         db
         {:BookQuality/Poor 0
          :BookQuality/Good 1
          :BookQuality/Excellent 2}
         eid quality)
    [[:db/add eid :book/quality quality]]
    []))