密码中的嵌套has

本文介绍了密码中的嵌套has_many关系的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有一个嵌套的has_many关系，试图映射到json结果.

I have a nested has_many relationship that I'm trying to map to a json result.

博客中的以下示例显示了我想做的事情，除了它不是嵌套的

The following example from the blog shows the kind of thing I want to do, except it's not nested

MATCH (a:Person { name: "Andres" })-[:FATHER_OF]->(child) RETURN {name:a.name, kids:collect(child.name)} as document

我想要的是这样的

MATCH (a:Person { name: "Andres" })-[:FATHER_OF]->(child)-[:has_read]->(book)-[:has_chapter]->(chapter) RETURN {name:a.name, kids:collect({"name":child.name, has_read:collect(book)})} as document

在这种情况下，我想返回一个结构如下的json对象:

In this case I would like to return a json object of a structure like this:

{ "name": "Andres" "kids": [ { "name":"Bob" "has_read": [ { "name":"Lord of the Rings", "chapters": ["chapter1","chapter2","chapter3"] }, { "name":"The Hobbit", "chapters": ["An unexpected party","Roast mutton"] } ] }, { "name":"George" "has_read": [ { "name":"Lord of the Rings", "chapters": ["chapter1","chapter2","chapter3"] }, { "name":"Silmarillion", "chapters": ["chapter1","chapter2"] } ] } ] }

推荐答案

可以尝试:

如果您与该章保持一致，则需要与众不同 collect(distinct book.title)否则.

if you keep the match to the chapter you will need distinct collect(distinct book.title) otherwise not.

MATCH (a:Person { name: "Andres" })-[:FATHER_OF]->(child), (child)-[:has_read]->(book)-[:has_chapter]->(chapter) WITH a,child,collect(distinct book.title) as books RETURN {name:a.name, kids:collect({name:child.name, has_read:books})} as document

哦，如果您也想在结果中包括这些章节，则只需添加一个带有:)

Oh and if you want to include the chapters in the results too, then just add another with :)

MATCH (a:Person { name: "Andres" })-[:FATHER_OF]->(child), (child)-[:has_read]->(book)-[:has_chapter]->(chapter) WITH a,child, {title: book.title, chapters: collect(chapter.title)} as book_doc WITH a,child, collect(book_doc) as books RETURN {name:a.name, kids:collect({name:child.name, has_read:books})} as document

请参阅: console.neo4j/r/kua2pi