Py2neo - 在 writebatch 中创建关系

Question

我使用 py2neo 将数据转储到 Neo4j 数据库中。

有了这个

batch = neo4j.WriteBatch(graph_db)
batch.create(node(name="Alice"))
batch.create(node(name="Bob"))
batch.create(rel(0, "KNOWS", 1))
results = batch.submit()

我可以使用同一批次中的新节点创建关系。

但是，如果我尝试与在批处理之前已经创建的节点创建关系，如下所示：

n = graph_db.create({"name": "Smith"})
batch = neo4j.WriteBatch(graph_db)
batch.create(node(name="Alice"))
batch.create(rel(0, "KNOWS", n))
results = batch.submit()

它失败了*。 将如何继续创建一批与先前创建的节点有关系的节点？

使用 py2neo 1.5.1 和 Neo4j 1.9.2

谢谢

• 错误信息：

SystemError: {u'stacktrace': [u'org.neo4j.server.rest.batch.NonStreamingBatchOperations.invoke(NonStreamingBatchOperations.java:63)', u'org.neo4j.server.rest.batch.BatchOperations。 performRequest(BatchOperations.java:188)', u'org.neo4j.server.rest.batch.BatchOperations.parseAndPerform(BatchOperations.java:159)', u'org.neo4j.server.rest.batch.NonStreamingBatchOperations.performBatchJobs( NonStreamingBatchOperations.java:48)', u'org.neo4j.server.rest.web.BatchOperationService.batchProcess(BatchOperationService.java:117)', u'org.neo4j.server.rest.web.BatchOperationService.performBatchOperations(BatchOperationService. java:72)', u'java.lang.reflect.Method.invoke(Method.java:606)', u'org.neo4j.server.rest.security.SecurityFilter.doFilter(SecurityFilter.java:112)'] , u'message': u'{\n "message" : "对于输入字符串: \"5078\')]}\"",\n "exception" : "BadInputException",\n "fullname" : "org .neo4j.server.rest.repr.BadInputException",\n "stacktrace" : [ "org.neo4j.server.rest.web.RestfulGraphDa tabbase.extractNodeId(RestfulGraphDatabase.java:171)”, “org.neo4j.server.rest.web.RestfulGraphDatabase.createRelationship(RestfulGraphDatabase.java:410)”, “java.lang.reflect.Method.invoke(Method.java: 606)"、"org.neo4j.server.rest.security.SecurityFilter.doFilter(SecurityFilter.java:112)"、"org.neo4j.server.web.Jetty6WebServer.invokeDirectly(Jetty6WebServer.java:302)"、"org .neo4j.server.rest.batch.NonStreamingBatchOperations.invoke（NonStreamingBatchOperations.java:55）”，“org.neo4j.server.rest.batch.BatchOperations.performRequest（BatchOperations.java:188）”，“org.neo4j.server .rest.batch.BatchOperations.parseAndPerform（BatchOperations.java:159）”，“org.neo4j.server.rest.batch.NonStreamingBatchOperations.performBatchJobs（NonStreamingBatchOperations.java:48）”，“org.neo4j.server.rest.web .BatchOperationService.batchProcess(BatchOperationService.java:117)”、“org.neo4j.server.rest.web.BatchOperationService.performBatchOperations(BatchOperationService.java:72)”、“java.lang.reflect.Method.invoke(Met hod.java:606)", "org.neo4j.server.rest.security.SecurityFilter.doFilter(SecurityFilter.java:112)" ],\n "cause" : {\n "message" : "对于输入字符串： \"5078\')]}\"",\n "exception" : "NumberFormatException",\n "stacktrace" : [ "java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)", "java.lang .Long.parseLong(Long.java:441)"、"java.lang.Long.parseLong(Long.java:483)"、"org.neo4j.server.rest.web.RestfulGraphDatabase.extractNodeId(RestfulGraphDatabase.java:167 )”、“org.neo4j.server.rest.web.RestfulGraphDatabase.createRelationship(RestfulGraphDatabase.java:410)”、“java.lang.reflect.Method.invoke(Method.java:606)”、“org.neo4j. server.rest.security.SecurityFilter.doFilter(SecurityFilter.java:112)”、“org.neo4j.server.web.Jetty6WebServer.invokeDirectly(Jetty6WebServer.java:302)”、“org.neo4j.server.rest.batch. NonStreamingBatchOperations.invoke(NonStreamingBatchOperations.java:55)", "org.neo4j.server.rest.batch.BatchOperations.performRequest(BatchOperations.java:188) ", "org.neo4j.server.rest.batch.BatchOperations.parseAndPerform(BatchOperations.java:159)", "org.neo4j.server.rest.batch.NonStreamingBatchOperations.performBatchJobs(NonStreamingBatchOperations.java:48)", "org .neo4j.server.rest.web.BatchOperationService.batchProcess（BatchOperationService.java:117）”，“org.neo4j.server.rest.web.BatchOperationService.performBatchOperations（BatchOperationService.java:72）”，“java.lang.reflect .Method.invoke(Method.java:606)", "org.neo4j.server.rest.security.SecurityFilter.doFilter(SecurityFilter.java:112)" ],\n "fullname" : "java.lang.NumberFormatException" \n }\n}', u'fullname': u'org.neo4j.server.rest.domain.BatchOperationFailedException', u'exception': u'BatchOperationFailedException'}

Answer 1

在您的代码示例中，n 实际上将包含节点列表，而不是单个节点（请参阅create 方法的警告）。所以，而不是...

n = graph_db.create({"name": "Smith"})

...你可能想要...

n, = graph_db.create({"name": "Smith"})