[英]Unable to create relationship between two nodes in Neo4J database using Cypher query in Java
[英]Query two nodes from neo4j database using java
我是Neo4j的新手,我想查询仅包含节点的Neo4j数据库,以便根据已有的2个列表在它们之间创建链接。
例如,我想将名称为List A
的节点与名称为List B
节点连接起来。
这是我写的代码:
public class Main {
public static void main(String[] args) {
GraphDatabaseFactory graphDbFactory = new GraphDatabaseFactory();
GraphDatabaseService graphDb = graphDbFactory.newEmbeddedDatabase("C:\\Zakaria\\NeoTests\\Tetralecture");
ExecutionEngine execEngine = new ExecutionEngine(graphDb);
/* Here is a loop to read from listA and listB so no need to worry about them */
try (Transaction ignored = graphDb.beginTx()) {
String query = "MATCH (auteur1:AUTEUR{Name:'" + listA.get(i) + "'}), (auteur2:AUTEUR{Name:'" + listB.get(j) + "'}) return auteur1, auteur2";
ExecutionResult execResult = execEngine.execute(query);
Iterator<Node> aut_column = execResult.columnAs("auteur1");
for(Node node : IteratorUtil.asIterable(aut_column)) {
String nodeResult = node + " : " + node.getProperty("Name");
System.out.println(nodeResult);
}
}
}
}
本示例仅显示来自一个auteur1
一个作者列表,我希望能够同时显示两个作者。
如果可以,我认为从两个列表中删除节点并在它们之间创建链接会更容易。
谢谢你的帮助!
这对您有用吗?
public class Main {
public static void main(String[] args) {
GraphDatabaseFactory graphDbFactory = new GraphDatabaseFactory();
GraphDatabaseService graphDb = graphDbFactory.newEmbeddedDatabase("C:\\Zakaria\\NeoTests\\Tetralecture");
ExecutionEngine execEngine = new ExecutionEngine(graphDb);
/* Here is a loop to read from listA and listB so no need to worry about them */
try (Transaction ignored = graphDb.beginTx()) {
String query = "MATCH (auteur1:AUTEUR{Name:'" + listA.get(i) + "'}), (auteur2:AUTEUR{Name:'" + listB.get(j) + "'}) return auteur1, auteur2";
ExecutionResult execResult = execEngine.execute(query);
for(Map<String, Object> row : execResult) {
final Node node1 = (Node)row.get("auteur1");
final Node node2 = (Node)row.get("auteur2");
String nodeResult = node1 + " : " + node1.getProperty("Name") + "; " + node2 + " : " + node2.getProperty("Name");
System.out.println(nodeResult);
}
}
}
}
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