从Neo4j中的csv加载节点时有条件地创建节点和关系 [英] Create nodes and relations conditionally when loading nodes from csv in Neo4j

问题描述

我有一个csv格式的数据集。其中一个字段是类型，如枚举。基于这种类型，我需要创建不同类型的节点和关系时使用csv load加载数据。你可以在csv中调用一个具有定义其子类型的属性的超类型的行。

我真的不知道如何在cypher 。

解决方案

这个有条件语句的文档有帮助。

下面是一个基于列值加载的简单示例：

数据：
a，b
Ford，car
Chevy，truck
Mazda，car
GMC，truck
F150，truck

Cypher代码：

加载csv，其头文件为file：/testfile.csv作为行
FOREACH（ignoreMe IN CASE WHEN trim（row.b）= truckTHEN [1] ELSE [] END | MERGE（p：Truck {vehicleType：row.a}））
FOREACH（ignoreMe IN CASE WHEN trim ELSE [] END | MERGE（p：Car {vehicleType：row.a}））


完成后，您将创建不同类型的节点。

I have a data set in csv format. One of the fields is a type, like an enumeration. Based on this type I need to create different types nodes and relations when loading the data using csv load. You could call a row in the csv for a super type having an attribute defining its subtype.

I'm not really able to figure out how this can be done in cypher. Is my only option to split the one csv file into a csv file per type and run different cyphers ?

解决方案

This document on conditional statements helps.

Here is a simple example for loading based on a column value:

Data: a,b Ford,car Chevy,truck Mazda,car GMC,truck F150,truck

Cypher code:

load csv with headers from "file:/testfile.csv" as row
FOREACH(ignoreMe IN CASE WHEN trim(row.b) = "truck" THEN [1] ELSE [] END | MERGE (p:Truck {vehicleType: row.a}))
FOREACH(ignoreMe IN CASE WHEN trim(row.b) = "car" THEN [1] ELSE [] END | MERGE (p:Car {vehicleType: row.a}))

When you are done, you will have nodes created of different types.

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