Question

我使用以下查询将数据从csv加载到Neo4j：

CREATE CONSTRAINT ON (e:Entity) ASSERT e.entity IS UNIQUE;

USING PERIODIC COMMIT 1000
LOAD CSV WITH HEADERS FROM 'file:/file1.csv' AS line FIELDTERMINATOR '|'

WITH line 

MERGE (e0:Entity {entity: line.entities_0_entity})
ON CREATE SET e0.confidence = toFloat(line.entities_0_confidence)

MERGE (e1:Entity {entity: line.entities_1_entity})
ON CREATE SET e1.confidence = toFloat(line.entities_1_confidence)

MERGE (e0)-[r:REL {name: line.relation_relation, confidence: toFloat(line.relation_confidence)}]->(e1)

RETURN *

任何人都可以告诉等效查询从Neo4j命令行加载数据或者在浏览器中动态更改文件名或者像“file：/ file *”那样传递文件...

Answer 1

如果要多次处理相同的Cypher语句，每次调整一个或多个值，可以使用APOC过程apoc.periodic.iterate。

在您的示例中，您希望事先执行CREATE CONSTRAINT语句（并且只需执行一次）。

例如：

CALL apoc.periodic.iterate(
  "
    WITH ['file1', 'x', 'y'] AS filenames,
    UNWIND filenames AS name
    RETURN name;
  ",
  "
    USING PERIODIC COMMIT 1000
    LOAD CSV WITH HEADERS FROM 'file:/' + {name} + '.csv' AS line FIELDTERMINATOR '|'
    WITH line 
    MERGE (e0:Entity {entity: line.entities_0_entity})
    ON CREATE SET e0.confidence = toFloat(line.entities_0_confidence)
    MERGE (e1:Entity {entity: line.entities_1_entity})
    ON CREATE SET e1.confidence = toFloat(line.entities_1_confidence)
    MERGE (e0)-[r:REL {name: line.relation_relation, confidence: toFloat(line.relation_confidence)}]->(e1);
  ",
  {});

此查询将执行LOAD CSV语句3次（顺序，因为默认情况下该过程的parallel选项为false），传递其中一个字符串（＆＃34; file1＆＃34;，＆＃34; y＆＃34;和＆＃34; z＆＃34;）每次都作为name参数。

Answer 2

您可以简单地将所有文件放在neo4j的导入目录中，然后使用bash脚本将它们全部加载：

#!bin/sh

for file in /Users/ikwattro/dev/_graphs/310/import/*
do
    curl -H "Content-Type: application/json" \
        -d '{"statements": [{"statement": "LOAD CSV WITH HEADERS FROM file:///$file AS row ..."}]' \
        http://localhost:7474/db/data/transaction/commit
done

Neo4j本身没有标准方法可以指定要导入的多个文件。

密码中的批处理或从Neo4j浏览器上传多个文件

2 个答案: