neo4j

问题 I'm using Neo4j 2.0.0-M06. Just learning Cypher and reading the docs. In my mind this query would work, but I should be so lucky... I'm importing tweets to a mysql-database, and from there importing them to neo4j. If a tweet is already existing in the Neo4j database, it should be updated. My query: MATCH (y:Tweet:Socialmedia) WHERE HAS (y.tweet_id) AND y.tweet_id = '123' CREATE UNIQUE (n:Tweet:Socialmedia { body : 'This is a tweet', tweet_id : '123', tweet_userid : '321', tweet_username :

问题 Neo4j's legacy indexes offer functionality like doing Lucene queries on them, or indexing arbitrary key/value pairs. For example, if my User node looks like this: (me { FirstName: 'John', LastName: 'Doe'}) , I can put this user in a legacy index with a key of FullName , a value of 'john doe' , and I can get this user and other users whose name starts with a 'j' with this Cypher query: start withj=node:User("FullName:j*") return withj; I'm thinking of converting my legacy index based

问题 I have 2 nodes: (A), (B), connected by [:FRIEND] When I run the following command, start n = node(*) match (n)-[r:FRIEND]-(b) return n.name, b.name; it returns 2 rows: A, B and B, A. I wonder, how to make it return only one record, because the relationship is bidirectional, A -[:FRIEND]-B and B-[:FRIEND]-A is considered same result. Thanks. 回答1: One trick is to add a where on the IDs, so you get them in a consistent order as well: start n = node(*) match (n)-[r:FRIEND]-(b) where id(n) < id(b)

问题 I have a graph with many different elements but every element has a property "ID". Now i would like to CREATE INDEX ON :anyType(ID) How can i trigger the index creation for any type? 回答1: CREATE INDEX ON takes a label, and cannot be called without the label (nor can it be called with multiple labels). So you'd have to execute this for each label type. That is, you can't run: CREATE INDEX(ID) or CREATE INDEX ON:*(ID) You need to run: CREATE INDEX ON:label(ID) 来源： https://stackoverflow.com

问题 I'm trying to create a relationship between nodes dynamically. The problem I am having is that I am unable to use a variable to specify the relationship type. For example, I have the data: { nodes: [ { "name":"Node1" }, ... ], relationships: [ { "sourceNode": "Node1", "destinationNode": "Node2", "relationshipType": "FRIEND" }, ... ] } Assume all nodes have been created. I now want to create relationships between nodes of type relationshipType . I'm trying to do this like so: WITH {json} AS

问题 I'm building a Neo4j (2.2.2) unmanaged extension and I can't figure out why the following method is throwing 415: unsupported media type when I post requests with properly-formatted JSON bodies and Content-Type:application/json headers. @POST @Path("/create") @Consumes(MediaType.APPLICATION_JSON) public Response createFoo(FooBar input) { //not relevant } This is the FooBar class I want the JSON to be mapped to: @XmlRootElement public class FooBar implements Serializable { String title; public

问题 I'm searching for a way to remove every property, of any node in the DB, having a specific value using Cypher. Context I got a csv bulk file from a relational table with plenty of NULL values. LOAD CSV brings them as values. Removing them (replacing them with empty '' within the csv file) resulted in the same issue (properties without values). Tried many (many) Cypher operations to discard NULL values but nothing worked. Can't find anything in the docs neither by Googling. Can this be done

问题 How to delete multiple nodes, (NOT ALL) in neo4j? I have this query MATCH (n) where n.name IS NULL delete n It returns more than one node, I want to delete all those nodes(All nodes, which are mistakenly created thats why become null). The error, I am facing is javax.transaction.HeuristicRollbackException: Failed to commit transaction Transaction(11, owner:"qtp16626756-84")[STATUS_NO_TRANSACTION,Resources=1], transaction rolled back ---> javax.transaction.xa.XAException CASE 2: What to do in

问题 I would like to return for a given node-id related nodes and their relationships props For example: -> defines a bi direction relationship with property timestamp 1234->777 777->1234 1234->999 999->1234 1234->888 888->1234 1234,777,888,999 are node-ids When I execute this: final PreparedStatement ps = conn.prepareStatement("start a = node(1234) match (a)-[k:nearby*]->(b) where a<>b return DISTINCT b, k"); ResultSet rs = ps.executeQuery(); while (rs.next()) { Map result = (Map<String, Object>)

问题 I'm trying to import a fair amount of data into Neo4j, which it takes too long to be imported using the LOAD CSV way. For that reason I'm trying with the neo4j-import command but I got the following error and I haven't found any information about it or what it means exactly. The error is: 2015-04-29 14:34:06.225+0000 ERROR [org.neo4j]: Error during import Mixing specified and unspecified group belongings in a single import isn't supported java.lang.RuntimeException: Mixing specified and