我是learning about Datomic queries并对如何做好奇"parameter queries."
这就是我想出的:
(d/q '[:find ?n ?x :where [?n :likes ?x] [(= ?x "pizza")]]
[['ethel :likes "sushi"]['fred :likes "pizza"]])
=> #<HashSet [[fred "pizza"]]>
这是它,还是有更简洁/惯用的方式来实现上述目标?
我是learning about Datomic queries并对如何做好奇"parameter queries."
这就是我想出的:
(d/q '[:find ?n ?x :where [?n :likes ?x] [(= ?x "pizza")]]
[['ethel :likes "sushi"]['fred :likes "pizza"]])
=> #<HashSet [[fred "pizza"]]>
这是它,还是有更简洁/惯用的方式来实现上述目标?
1 回答
答案在Datomic tutorial的"Advanced Queries"部分
使用
:in
子句:in $ ?x
是参数子句,尾随"sushi"
绑定到?x