嵌套has_many關係在密碼

Question

我有一個嵌套的has_many關係，我試圖映射到json結果。

從博客下面的例子顯示我想要做的事情，但它不是嵌套

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

我想的卻是這樣的

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 

在這種情況下，我想返回像這樣的結構的json對象：

{ 
    "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"] 
          } 
         ] 
      } 

      ] 
} 

Answer 1

你可以試試：

如果你保持匹配的章節，你將需要不同的 collect(distinct book.title)否則不是。

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，如果你想在結果中包括章節也是如此，那麼只需添加另一個與:)

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 

見： http://console.neo4j.org/r/kua2pi