Question

我有一个DB，里面有他们参加的学生和课程。目标是找到所有具有相同姓氏的学生参加相同的课程并返回他们的firstNames和courseNames。 (s:Student)-[r:ENROLLEDIN]->(c:Course)

我尝试了很多东西，但我相信我还在想SQL。

如何考虑关系，在同一个类的节点上比较相同的属性值？我用Google搜索了，但没有找到答案。

尽量不要过多地减去我，我刚开始学习这个东西。提前谢谢。

Answer 1

下面是一个简单的查询，可以找到所有参加同一课程的姓氏相同的学生：

MATCH (s1:Student)-[:ENROLLEDIN]->(c1:Course),(s2:Student)-[:ENROLLEDIN]->(c2:Course)
WHERE s1.lastName = s2.lastName AND c1.name = c2.name
RETURN DISTINCT s1.firstName, c2.name ORDER BY s1.firstName;

Answer 2

所以，我认为这个查询应该有效：

// match students and courses when students have the same name
MATCH (s1:Student)-[:ENROLLEDIN]->(c1:Course),
        (s2:Student)-[:ENROLLEDIN]->(c2:Course)
WHERE s1.lastname = s2.lastname
// order by c1
WITH s1, s2, c1, c2 ORDER BY c1
// collect c1 as c1s, order by c2
WITH s1, s2, c2, collect(c1) AS c1s ORDER BY c2
// collect c2 as c2s. Pass to the next context when
// c1s = c2s. The array order matters.
WITH s1, s2, collect(c2) as c2s, c1s 
WHERE c1s = c2s
RETURN s1.firstName, s2.firstName, c1s

Neo4J尝试查找具有匹配属性值的所有节点

2 个答案: