I have imported a CSV where each Node contains 3 columns. id, parent_id, and title. This is a simple tree structure i had in mysql. Now i need to create the relationships between those nodes considering the parent_id data. So each node to node will have 2 relationships as parent and child. Im really new to node4j and suggestions ?
i tried following, but no luck
MATCH (b:Branch {id}), (bb:Branch {parent_id})
CREATE (b)-[:PARENT]->(bb)
It seems as though your cypher is very close. The first thing you are going to want to do is create an index on the id and parent_id properties for the label Branch.
CREATE INDEX ON :Branch(id)
CREATE INDEX ON :Branch(parent_id)
Once you have indexes created you want to match all of the nodes with the label Branch (I would limit this with a specific value to start to make sure you create exactly what you want) and for each find the corresponding parent by matching on your indexed attributes.
MATCH (b:Branch), (bb:Branch)
WHERE b.id = ???
AND b.parent_id = bb.id
CREATE (b)-[:PARENT]->(bb)
Once you have proved this out on one branch and you get the results you expect I would run it for more branches at once. You could still choose to do it in batches depending on the number of branches in your graph.
After you have created all of the :PARENT relationships you could optionally remove all of the parent_id properties.
MATCH (b:Branch)-[:PARENT]->(:Branch)
WHERE exists(b.parent_id)
REMOVE b.parent_id
Related
I have a few Realtionships in Neo4J with the label "[r:Absatraction]". They all have a Property on them like "SysML:refine" or "SysML:trace" or "SysML:verify".
These "Abstractions connect differently labeled nodes. Now I want Neo4j to replace the Label "Abstraction" with the labels from the "SysML" Property. So that on the graph one can see "[r:refine],[r:verify]...".
I tried: apoc.create.addLabels, but it only seems to work for nodes.
Is there a way to do that?
In neo4j terminology, a relationship must have a single "type" -- not an optional set of "labels" (which are only for nodes). Furthermore, a relationship's type cannot be changed.
So, to do what you want, you'd have to create new relationships (with the desired types) and delete the old ones.
For example, here's is how you can use the APOC procedure apoc.create.relationship to create new relationships with the right types (and with the same properties as the old relationships except for SysML), and delete the old relationships:
MATCH (a:Foo)-[r:Abstraction]->(b:Foo)
CALL apoc.create.relationship(a, r.SysML, apoc.map.removeKey(PROPERTIES(r), 'SysML'), b) YIELD rel
DELETE r
RETURN rel
It is not possible to rename realtionships so one has to create a new one.
Example string for this problem:
match (a)-[old:Abstraction]->(b) where old.SysML = "Verify"
create (a)-[new:Verify]->(b)
delete old
I have a graph containing some nodes with :SubSystem labels. I want to add a new node with a :Document label and create relationships with each of the existing :SubSystem nodes.
When I execute this statement:
MATCH (s:SubSystem)
CREATE (d:Document {title:'New Document'})
CREATE (d)-[:DEPICTS]->(s);
I was surprised when Neo4j created a new :Document node for each :SubSystem. I have 12 sub-systems, so I ended up with 12 new documents each related to one sub-system. I would have expected this behavior had I written:
MATCH (s:SubSystem)
CREATE (:Document {title:'New Document'})-[:DEPICTS]->(s);
But I was expecting that separating the CREATE clauses would create 1 document then create relationships between that document and each of the sub-systems.
Can someone explain why this doesn't work as I was expecting.
EDIT:
I found a solution. This statement does what I wanted, but I still think my original attempt should have worked.
CREATE (d:Document {title:'New Document'})
WITH d MATCH (s:SubSystem) CREATE (d)-[:DEPICTS]->(s);
A MATCH clause generates one or more result rows (or aborts the query if no results are found). A subsequent read/write clause would be executed once per row. Rearranging the order of the clauses, as you did, is one way to work around that (when possible).
consider a situation . There is a company say A. So its a root node. Node is created (n: Comapny{id:'a',title:'A' parentId:''}) . A adds 2 depts say IT Team, the testing team. .So Node is created
({cl:ComapnyLeaf{id:'itTeam',title:'IT Team',parentId:'a'}); ({cl:ComapnyLeaf{id:'testingTeam',title:'TESTING Team',parentId:'a'}); Now it adds emapolyee
({cl:ComapnyLeaf{id:'emp1',title:'Emp 1',parentId:'itTeam'});
so while creating nodes relationship between them should be created my final out will look like
Company(A) < ---- child--- it Team <----child---emp1
< ---- child--- Testing Team
I think you need to recheck your query and your desired output, you have misspellings and bad syntax in there, and your output doesn't reflect your input. The testing team should end up being the child of :Company node a, not the Emp 1 :CompanyLeaf node.
Let's first create the nodes like this (you'll need to enable the multi-statement query editor in the Neo4j Browser preferences):
CREATE (n:Company:Node {id:'a', title:'A'});
CREATE (cl:CompanyLeaf:Node {id:'itTeam', title:'IT Team', parentId:'a'});
CREATE (cl:CompanyLeaf:Node {id:'testingTeam', title:'TESTING Team', parentId:'a'});
CREATE (cl:CompanyLeaf:Node {id:'emp1', title:'Emp 1', parentId:'itTeam'});
Then let's add an index on :Node(id) to support the fast lookups we'll need to create the relationships.
CREATE INDEX ON :Node(id)
Then for checking all :CompanyLeaf nodes in the graph and attaching them to a node with the given id as the parent, we can use this:
MATCH (c:CompanyLeaf)
WHERE NOT (c)-[:PARENT]->()
MATCH (parent:Node {id:c.parentId})
CREATE (c)-[:PARENT]->(parent)
The WHERE NOT clause here makes sure we don't create duplicate relationships in case we already ran the query, or in case we do several imports of nodes with relationship creation happening in between.
Also this is creating :PARENT relationships pointing the parent, since your example didn't make sense with :child relationships pointing to the parent.
i have two csv files the first one is like
movies.csv
movieId | title | genres
links.csv
movieId | tmdbId | imdbId
ive tried this cypher query
USING PERIODIC COMMIT 500
LOAD CSV WITH HEADERS FROM "file:///links.csv" AS row
WITH row
MATCH (movie:Movie {id: toInt(row.movieId)})
MERGE (link)-[r:LINK]->(movie)
ON CREATE SET r.tmdbId = toInt(row.tmdbId)
this didnt work for me, it doesnt create new label "LINK" or form the relationship correctly,,
i want to be able when i have a movieId to get its corresponding tmdbId
t've tried several methods but none of them worked, im new to neo4k and still familiarised with sql
Your usage of link is as a variable, not a label (you would use :Link if you wanted to create a new node with that label), and it's not really clear what your link is supposed to be, as you don't have any ids or any properties on it. It's also not clear what you need other nodes for, as a movie node can easily have properties for related ids (so you look up the :Movie node by its movieId and then get the tmdbId from that node).
If you could provide more details about your use cases, and what you want to model and how it's connected, that would help.
EDIT
Okay, so it sounds like you're modeling :Movies, and you also want :Link nodes that hold both tmdbId and imdbId properties. As mentioned above, in reality you should just set the properties on the :Movie node itself and not bother with :Link nodes at all, but this is for the sake of getting used to neo4j, so okay.
First of all, to make sure our matches are fast as we build these relationships, we need unique constraints on nodes through their unique IDs.
CREATE CONSTRAINT ON (m:Movie)
ASSERT m.id IS UNIQUE
CREATE CONSTRAINT ON (l:Link)
ASSERT l.tmdbId IS UNIQUE
CREATE CONSTRAINT ON (l:Link)
ASSERT l.imdbId IS UNIQUE
Your import would be:
USING PERIODIC COMMIT 500
LOAD CSV WITH HEADERS FROM "file:///links.csv" AS row
WITH row
MATCH (movie:Movie {id: toInt(row.movieId)})
MERGE (link:Link{imdbId: toInt(row.imdbId), tmdbId: toInt(row.tmdbId)})
MERGE (link)-[:LINK]->(movie)
And a query to get the movie by one id would be:
MATCH (link:Link)-[:LINK]->(movie:Movie)
WHERE link.imdbId = 123
RETURN movie
You should be able to infer the query for going the opposite direction, starting with a movieId and traversing the :LINK relationship to the :Link node (you may want to change one of these, as having the same name for a node label and a relationship type might get confusing since you're new to this) to get the relevant ID.
In Neo4j, I am trying to load a CSV file whilst creating a relationship between nodes based on the condition that a certain property is matched.
My Cypher code is:
LOAD CSV WITH HEADERS FROM "file:C:/Users/George.Kyle/Simple/Simple scream v3.csv" AS
csvLine
MATCH (g:simplepages { page: csvLine.page}),(y:simplepages {pagekeyword: csvLine.keyword} )
MATCH (n:sensitiveskin)
WHERE g.keyword = n.keyword
CREATE (f)-[:_]->(n)
You can see I am trying to create a relationship between 'simplepages' and 'sensitiveskin' based on their keyword properties being the same.
The query is executing but relationships won't form.
What I hope for is that when I execute a query such as
MATCH (n:sensitiveskin) RETURN n LIMIT 25
You will see all nodes (both sensitive skin and simple pages) with auto-complete switched on.
CREATE (f)-[:_]->(n) is using an f variable that was not previously defined, so it is creating a new node (with no label or properties) instead, and then creating a relationship from that new node. I think you meant to use either g or y instead of f. (Probably y, since you don't otherwise use it?)