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cypher-在Neo4j中添加随机关系仅使用单个节点

(cypher - Adding random relationships in Neo4j only uses single node)

发布于 2019-07-06 22:33:27

我的结构如下所示:

Person   -[:HAS_HOBBY]->  Hobby

我正在随机生成500个节点和20个爱好节点,现在想在它们之间生成随机链接,以便每个人都有1个或多个爱好,但并不是每个人都有相同的爱好。

CALL apoc.periodic.iterate("
    match (p:Person),(h:Hobby) with p,h limit 1000 
    where rand() < 0.1 RETURN p,h ", 
    "CREATE (p)-[:HAS_HOBBY]->(h)", 
    {batchSize: 20000, parallel: true}) 
YIELD batches, total 
RETURN *

没有APOC功能,查询如下所示:

MATCH(p:Person),(h:Hobby)
WITH p,h
LIMIT 10000
WHERE rand() < 0.1
CREATE (p)-[:HAS_HOBBY]->(h)

这是我尝试过的查询,问题是所有人员节点都链接到一个单一的兴趣节点,因此仅使用了1/20个节点。

查询中是否缺少任何内容?还是我应该以其他方式解决这个问题?

我还尝试了通过FOREACH子句遍历所有节点或使用SKIPLIMIT通过笛卡尔乘积的不同方法

非常感谢!

编辑:

使用InverseFalcon进行查询apoc.periodic.iterate

call apoc.periodic.iterate("
// first generate your range of how many hobbies you want a person to have
// for this example, 1 to 5 hobbies
WITH range(1,5) as hobbiesRange
// next get all hobies in a list
MATCH (h:Hobby)
WITH collect(h) as hobbies, hobbiesRange
MATCH (p:Person)
// randomly pick number of hobbies in the range, use that to get a number of random hobbies
WITH p, apoc.coll.randomItems(hobbies, apoc.coll.randomItem(hobbiesRange)) as hobbies
// create relationships
    RETURN p,hobbies", 
"FOREACH (hobby in hobbies | CREATE (p)-[:HAS_HOBBY]->(hobby))", 
{batchSize: 1000, parallel: false});
Questioner
user6278182
Viewed
0
InverseFalcon 2019-07-08 08:32:14

在这种情况下,不使用iterate()会更容易,而要使用APOC的某些集合帮助器函数,例如那些用于从集合中获取随机项目的函数。像这样的东西:

// first generate your range of how many hobbies you want a person to have
// for this example, 1 to 5 hobbies
WITH range(1,5) as hobbiesRange
// next get all hobies in a list
MATCH (h:Hobby)
WITH collect(h) as hobbies, hobbiesRange
MATCH (p:Person)
// randomly pick number of hobbies in the range, use that to get a number of random hobbies
WITH p, apoc.coll.randomItems(hobbies, apoc.coll.randomItem(hobbiesRange)) as hobbies
// create relationships
FOREACH (hobby in hobbies | CREATE (p)-[:HAS_HOBBY]->(hobby))