Question

我在图数据库，原始机场和目的地机场和运营商中创建了3个节点。它们与名为“cancel_by”的财产相关联。

   MATCH (origin:origin_airport {name: row.ORIGIN}),
   (destination:dest_airport {name: row.DEST}),
   (carrier:Carrier {name: row.UNIQUE_CARRIER})
   CREATE (origin)-[:cancelled_by {cancellation: row.count}]->(carrier)
   CREATE (origin)-[:cancelled_by {cancellation: row.count}]->(destination)
   CREATE (origin)-[:operated_by {carrier: row.UNIQUE_CARRIER}]->(carrier)

cancelled_by保存特定运营商取消的值次数。我的输入文件格式如下：

ORIGIN  UNIQUE_CARRIER  DEST    Cancelled
 ABE    DL                ATL    1
 ABE    EV                ATL    1
 ABE    EV                DTW    3
 ABE    EV                ORD    3
 ABQ    DL                DFW    2
 ABQ    B6                JFK    2

这里我需要计算每个运营商的取消百分比。我期待的结果如下：

UNIQUE_CARRIER  DEST    Percentage_Cancelled
    DL                   25%
    EV                   58.33%
    B6                   16.66%

Example: Total number of cancellation = 12
No of cancellation for DL = 3
Percentage of cancellation for DL = (3/12)*100 = 25%

以下查询给出了每个运营商的取消总和：

 MATCH ()-[ca:cancelled_by]->(c:Carrier)
 RETURN c.name  AS Carrier, 
 SUM(toFloat(ca.cancellation)) As sum
 ORDER BY sum DESC
 LIMIT 10

我尝试了以下查询来计算百分比：

  MATCH ()-[ca:cancelled_by]->(c:Carrier)
  WITH SUM(toFloat(ca.cancellation)) As total
  MATCH ()-[ca:cancelled_by]->(c:Carrier)
  RETURN c.name  AS Carrier, 
  (toFloat(ca.cancellation)/total)*100 AS percent
  ORDER BY percent DESC
  LIMIT 10

但它不是通过分组来计算百分比，而是单独计算百分比。

     Carrier    sum
        DL    0.36862408915559364
        DL    0.34290612944706383
        DL    0.3171881697385341

如何使用Neo4j中的密码查询基于group_by计算百分比？

Answer 1

您在分组时忘记了每个运营商的总和，并且不一定总是使用强制转换来浮动 - 就在最后一次计算乘以浮点数时。

MATCH ()-[ca:cancelled_by]->(:Carrier)
  WITH SUM(ca.cancellation) As total
  MATCH ()-[ca:cancelled_by]->(c:Carrier)
RETURN c.name AS Carrier, 
       100.0 * SUM(ca.cancellation) / total AS percent
  ORDER BY percent DESC
  LIMIT 10

Answer 2

您好您可以尝试使用R dplyr包。使用链接操作%>%以及函数 group_by，summarize和transmute。 group_by和summarize 会给你每组内取消的金额。使用 transmute用于获取相对频率。

如何在Neo4j中使用Cypher查询分组并计算百分比

2 个答案: