neo4j

问题 In my application, I have what is essentially the syntax tree of a mathematical expression as neo4j graph... a picture is probably helpful: I'm wondering if it's possible to write a Cypher query that fully evaluates a tree like this for the top node, i.e.: gets the average of the connected inputs for Node 1.2, the max for 1.1.2 the average of 1.1.2 and 3 for Node 1.1 and finally returns the max of 1.2 and 1.1 as value for Node 1 The value is stored in the property status for the input nodes,

问题 The server had been running fine and dandy but suddenly stopped. Tried restarting but that didn't help. This is what the log says: 2015-02-18 15:07:58.092+0000 INFO [o.n.k.i.DiagnosticsManager]: --- SHUTDOWN diagnostics END --- 2015-02-18 15:07:58.336+0000 ERROR [o.n.s.CommunityBootstrapper]: Failed to start Neo Server on port [7474] org.neo4j.server.ServerStartupException: Starting Neo4j Server failed: Error starting org.neo4j.kernel.EmbeddedGraphDatabase, /var/lib/neo4j-community-2.1.4/data

问题 Is it possible to fetch Page results when using Spring Data Graph (Neo4J) as the data store? The findAll(Pageable) seems to be the only Pageable query availalble when using the GraphRepository . What I am looking for is Pageable APIs for other findBy***() like queries. Perhaps, there may be a completely different (recommended) way to Page results using Spring Data Graph. Thoughts on that are welcome as well! 回答1: Spring Data Neo4j (2.0 currently in SNAPSHOT but soon RC1) added Page support

问题 i am using neo4j graph db ,it used in Ruby on Rails , for example: i have 3 relationship between tom and jerry ,they cooperated to build 3 houses, and now i just want to match 1 of 3 ;how to write the query code??? i have tried this: this is my code: Neo4j::Session .query("MATCH (s1:Scholar)<-[r:COOPERATE]-(s2:Scholar) WHERE s1.id = #{@scholar.id} RETURN DISTINCT r ") and the result is all relationship between s1 and s2 were founded i just need 1 of relationship between s1 and s2 (i want to

问题 I'm struggling to find a definition of how to use the set cypher command with a parameter map Cheat sheet says use: SET n = {map} I have tried: START n = node(11379) SET n = {Name: "Random Test Change"} on my server I get error:- `.' expected but `=' found What am I doing wrong? 回答1: The map parameter could be used like this: String query = "START n = node(11379) SET n = {map}"; Map<String, String> myMap = new HashMap<String, String>(); myMap.put("Name", "Random Test Change"); Map<String,

问题 Is it possible in cypher to create different relationship between nodes based on the value of csv using the import functionality . Eg : For a given csv data product_id user_id action 1 1 VIEW 1 2 PURCHASE I need to create product node(product_id) , user node(user_id) and either VIEW or PURCHASE relationship between ' user ' and product node based on the value of ' action ' field in csv . Below are the approaches I tried . I know the syntax is incorrect but just to give an idea what I am

问题 I'm trying to debug a problem in the Neo4J Server plugin I'm writing. Is there a log I can output to? It's not obvious where or how to do this. 回答1: Good question. I think you could use Java Logging? That should be routed into the normal logging system. 来源： https://stackoverflow.com/questions/11704687/how-can-you-log-from-a-neo4j-server-plugin

问题 I am trying to remove leaf nodes in Neo4j, but only those with a single incoming relationship. (I'm so close.) I have a query that returns the exact node I wish to remove. However, when I replace the RETURN with DELETE, it removes more than the query returns. Here's the complete sequence: neo4j-sh (?)$ match (n)-[r]->(p) return n, r, p ; +------------------------------------------------------------+ | n | r | p | +------------------------------------------------------------+ | Node[2164]{name

问题 I have a graph which has categories and sub-categories and sub-sub-categories to indefinite level. How I can I get all this hierarchical data in one cipher query? I currently have this query : START category=node:categoryNameIndex(categoryName = "category") MATCH path = category <- [rel:parentCategory] - subcategory RETURN category, collect(subcategory); Which gives me following result: | category | collect(subcategory) | ==> +------------------------------------------------------------------

问题 Using http://console.neo4j.org as a sandbox, I have come across the following unexpected behavior: Statement 1 - Returns 1 row with a collection containing Neo Node MATCH (n:Crew) WHERE n.name="Neo" WITH COLLECT(n) AS c1 WITH c1+[] AS c2 RETURN c2 Statement 2 - Returns 0 rows (unexpected) MATCH (n:Crew) WHERE n.name="Neo" WITH COLLECT(n) AS c1 MATCH (n:Crew) WHERE n.name="NoOne" WITH c1+COLLECT(n) AS c2 RETURN c2 Statement 3 - Returns 1 row containing an empty collection MATCH (n:Crew) WHERE