赛弗-排序前的不同结果

Question

我对Cypher有点陌生，如果我错过了逻辑解决方案，很抱歉。(谢谢你的帮助:)

我所使用的图表用它们的出版日期制作了一个研究出版物网络，并创建了与出版物中提到的分子之间的关系。我试图了解每年增加的新分子的数量。

我试过：

MATCH (p:Publication)-->(m:Molecule)
RETURN DISTINCT datetime(p.releasedDate).year AS release, count(m) ORDER BY release 

这将返回一个列表，列出每年不同分子的数量，但仍然有可能(而且很可能)第一年的分子也在第二年，因为按顺序排列似乎是在不同的年份之前。

是否有一种方法首先列出所有不同的分子，然后按年排序？

再次感谢你的帮助。如果需要更多的信息，请告诉我。

Answer 1

我试图编写几个查询来说明一些选项：

// Number of molecule mentions per publication year
MATCH (p:Publication)-->(:Molecule)
WITH datetime(p.releasedDate).year AS release, count(*)


// Number of unique molecules mentioned per publication year
MATCH (p:Publication)-->(m:Molecule)
WITH datetime(p.releasedDate).year AS release, count(distinct m)


// Refactor so we know the year a molecule first mentioned
MATCH (p:Publication)-->(m:Molecule)
WITH m, min(datetime(p.releasedDate).year) as yearIntroduced


// Number of new molecules this year, and how many times where they mentioned
MATCH (p:Publication)-->(m:Molecule{yearIntroduced:2021})
RETURN m.name, count(*) as numberOfTimesMentioned


// Same but without refactoring
MATCH (p:Publication)-->(m:Molecule)
WITH m, min(datetime(p.releasedDate).year) as yearIntroduced
WHERE yearIntroduced=2021
MATCH (p:Publication)-->(m)
RETURN m.name, count(*) as numberOfTimesMentioned

我希望这能帮上忙！

Cypher手册中的聚合函数：https://neo4j.com/docs/cypher-manual/current/functions/aggregating/