我在“重温过去”部分的 datomic 教程遇到问题http://datomic.com/company/resources/tutorial.html
对于以下两个查询:
query = "[:find ?c :where [?c :community/name]]";
db_asOf_schema = conn.db().asOf(schema_tx_date);
System.out.println(Peer.q(query, db_asOf_schema).size()); // 0
db_since_data = conn.db().since(data_tx_date);
System.out.println(Peer.q(query, db_since_data).size()); // 0
我已经在 clojure 中尝试过这些命令,但无法让它们按照教程中的描述工作:
(since (db conn) (java.util.Date.) )
;; It should return 0 but returns the whole database instead
(def ts (q '[:find ?when :where [?tx :db/txInstant ?when]] (db conn)))
(count (since (db conn) (ffirst (reverse (sort ts))))))
;; returns 13, but should return 0
(count (as-of (db conn) (ffirst (sort ts)))))
;; returns 13, but should return 0
我不太确定这是正确的行为,我做错了什么吗?