clojure - セット全体を考慮したデータ型クエリをどのように作成するのでしょうか

Question

この種のクエリをデータ型で書くことは可能ですか?

• 最年長の子供の名前を見つける
• 体格指数 (体重 / 身長) が最も低い人を見つける

Answer 1

[:find (max ?tuple) :where 
    [?k :kid/age ?age] 
    [?k :kid/name ?name] 
    [(vector ?age ?name) ?tuple]

Note:

• the order of attributes in expression (vector ?age ?name) matters

• the query returns single result while we might expect a collection because there may be many kids of age that is the maximum in the set. You can use (max n ?tuple) to achieve that.

See also the Aggregates Returning Collections section in http://docs.datomic.com/query.html

If you have something more specific in mind, provide more details in the question and include your schema.