Question

我知道我使用的云代码如下

LOAD CSV WITH HEADERS FROM "https://gist.githubusercontent.com/jexp/d788e117129c3730a042/raw/c5f98f269b4a219ebb88bd3eb83d331f439a8201/people.csv"
  AS line
WITH line

WHERE line.PersonName IS NOT NULL

RETURN line.PersonName, coalesce(line.Company,"None")

但在我的情况下，line的许多属性为null。我可以在neo4j中迭代行（map结构）吗？可能像for k,v in line。

Answer 1

正如MicTech所说，COALESCE这里将完成这项工作。

对于你的问题，你可以迭代线图的k，v：

LOAD CSV 
WITH HEADERS FROM "https://gist.githubusercontent.com/ikwattro/29d133f8b2a8f022f5c9/raw/adbab9762ff0a15df18b49c9765ba3377d0e3ece/mockdata.csv" AS line 
WITH line
UNWIND keys(line) as k
RETURN k, line[k] as v

Answer 2

应该可以在2.3

WHERE none(k in keys(line) WHERE line[key] IS NULL)

在2.2.x中，我认为迭代的唯一方法是使用LOAD CSV FROM ... AS line语法将该行作为字符串集合返回。但是你失去了通过钥匙的访问权。

LOAD CSV FROM ... AS line 
WHERE NONE(value in line WHERE values IS null)
...

在neo4j中加载csv时如何轻松处理null？

2 个答案: