cypher

问题 I'm making a presentation about how some elements looks in Neo4j's Cypher and Titan's Gremlin i.e. add new vertex, look for relation etc. I have a problem with looking for cyclec. Is there any function in these 2 languages which can return a cycles i.e. for given vertex? 回答1: Here's how you do it in Gremlin: gremlin> g = TinkerGraphFactory.createTinkerGraph() ==>tinkergraph[vertices:6 edges:6] gremlin> g.v(2).addEdge("knows", g.v(6)) ==>e[0][2-knows->6] gremlin> g.v(6).addEdge("knows", g.v(1)

问题 I created a FullText index named: myFullTextIndex . When I want to search for the pattern: Hello World , the query looks like: START w=node:myFullTextIndex('title:"Hello World"') That works pretty well. However, I don't manage to search for the same string surrounded by wildcards. I expect a search on this pattern to return a result: *Hello World* I tried: START w=node:myFullTextIndex('title:"*Hello World*"') and START w=node:myFullTextIndex('title:*"Hello World"*') but doesn't work (syntax

问题 I wonder why this is considered an invalid use of aggregate functions in Neo4j's Cypher: MATCH (p:Project)-[:EMPLOYS]-(n:Person) SET p.youngest = MIN(n.age); While the following is considered a valid use case: MATCH (p:Project)-[:EMPLOYS]-(n:Person) RETURN p.name, MIN(n.age) AS youngest; How should I rewrite the first query to make it valid? 回答1: As for "why" your original Cypher attempt does not work, and the answer by @mah does work: Cypher only permits aggregation functions to be used in

问题 I have 2 nodes created in graph database, origin airport and destination airport. It is related by a property named 'delayed_by'. I need to associate multiple values to this property 'delayed_by'. There are various reasons for delays such as weather delay, carrier delay, nas delay and I need to link all of them to this property in graph database. I am expecting values as that of below tabular format in graph database ORIGIN DEST carr_delay weather_delay nas_delay ABE ATL 492 56 56 I used the

问题 I keep trying to run a apoc.load.csv procedure in the newest version of Neo4j 3.1.0, and APOC 3.1.0.3. CALL apoc.periodic.iterate('CALL apoc.load.csv("file:///data.csv", {sep:",", header:TRUE}) yield map ',' with {map} as map MATCH (t:Tweet{id:toFloat(map.tweet_id)}) SET t.clean_text = map.clean_text, t.positive_score = toInt(map.nb_positive), t.negative_score = toInt(map.nb_negative), t.sentiment_score = toInt(map.score)', {batchSize:5000, parallel:true}) Error: Failed to invoke procedure

问题 I have started learning cypher query for using graphical database. How should i get the values of all the nodes related to a super node. I am trying out the following query in console but its not working: start a=node(2) match (a)-[:TYPE*]<-(node) return node; node(2) is the super node. and the relation by which all other nodes are connected to a super node is TYPE. How should i correct my query.? Error : SyntaxException: expected - 回答1: You're representing the relationship wrong, try start a

问题 I need to calculate how many times a composer's pieces of music were performed per decade, then return only the one piece with the most performances per decade. This cypher does everything except filter all but the highest counts per decade. match (c:Composer)-[:CREATED_BY]-(w:Work)<-[*..2]-(prog:Program) WHERE c.lastname =~ '(?i).*stravinsky.*' WITH w.title AS Title, prog.title AS Program, LEFT(prog.date, 3)+"0" AS Decade RETURN Decade, Title, COUNT(Program) AS Total ORDER BY Decade, Total

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 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