Neo4j的Cypher :只在填充数据库时创建1到n的关系

Question

最近，我尝试使用以下代码填充neo4j测试数据库：

WITH ["Paul","Graham","Voord","Heisenberg","Earles","Grey","Herzog","Griffith","Rogers","Huxley","Waldorf","Astor","Mellon","Humphrey","Messerschmidt","Carmichael","Buchanan","Dalton","Valentino","Meyerholz","Ellington","Abernathy","Harrington","Monroe","Rutherford","Vanderbilt","Montgomery","Worthington","Fitzwilliam","Covington","Hollingsworth"]
AS names,
["Associates",""]
AS suffixes
FOREACH (r IN range(0,49) | CREATE (:Societe {id:10000+r, name:names[r % size(names)]+" & "+names[(r+3) % size(names)]+" "+suffixes[r % size(suffixes)]}));

FOREACH (r IN range(0,99) | CREATE (:Dossier {id:20000+r, Numero:"0"+(r*4)+100}));

MATCH (s:Societe),(d:Dossier)
WITH s,d
WHERE rand() < 0.1
CREATE (s)-[:CONTAINS]->(d);

但是，正如你可能已经猜到的，最后四行在我的(：档案)和我的(：社交)之间建立了n到n的关系。我最初想要的是在这两者之间建立一个1到n的关系，这样一个(：档案)最多可以链接到一个(:Societe)。

知道怎么做吗？

谢谢。

Answer 1

尼古拉斯

这里有一些Cypher来代替你最后的4行，这可能会让你达到你想去的地方。

MATCH (s:Societe)
WITH s
MATCH (d:Dossier)
WHERE NOT (d)<-[:CONTAINS]-() AND RAND() < 0.1
CREATE (s)-[:CONTAINS]->(d);

MATCH (d:Dossier)-[r:CONTAINS]-()
WITH d, collect(r) AS rels1
WITH d, rels1[1..] AS rels2
FOREACH(q IN rels2 | DELETE q)

第一部分减少了互连的数量，但没有使1比n(这让我感到困惑，但这就是它的方式)。第二部分梳理这些关系，以便每个档案都与法国兴业银行( societe )相关。你可能会有没有分配给兴业银行的档案，但你可以找到和删除那些。

恩惠与和平

吉姆

Answer 2

你可以过滤掉已经有一个法国兴业银行的档案。

MATCH (s:Societe), (d:Dossier)
WITH s,d
WHERE rand() < 0.1 and NOT (s)-[:CONTAINS]->()
CREATE (s)-[:CONTAINS]->(d);