Question

我有一个csv，我想在一个属性中使用多个列。但并非所有列都同时填充。

LOAD CSV WITH HEADERS FROM "file:c:/Users/emp.csv" AS row
CREATE (:Employee {ID: row.EID, Name: row.ENAME, Language: [row.L1, row.L2 , 
row.L3]});

此处，L1或L2或L3列中的某些值为空。

我收到错误：＆＃39;包含空值的集合无法存储在属性中。＆＃39;

我该如何解决这个问题？

Answer 1

这可能对您有用：

LOAD CSV WITH HEADERS FROM "file:c:/Users/emp.csv" AS row
UNWIND [row.L1, row.L2, row.L3] AS x
WITH row, COLLECT(x) AS langs
CREATE (:Employee {ID: row.EID, Name: row.ENAME, Language: langs});

UNWIND子句将L1，L2和L3放在不同的数据行中;并且COLLECT聚合函数再次将它们收集在一起，但忽略任何NULL值。

Answer 2

你可以尝试使用distinct来过滤掉空值

LOAD CSV WITH HEADERS FROM "file:c:/Users/emp.csv" AS row
WITH *, distinct(row.L1 + row.L2 + row.L3) as langs 
CREATE (:Employee {ID: row.EID, Name: row.ENAME, Language: langs});

Neo4j：包含空值的集合无法存储在属性中

2 个答案: