Assuming you’re referring to Neo4j’s internal node id: MATCH (p:Person) where ID(p)=1 OPTIONAL MATCH (p)-[r]-() //drops p’s relations DELETE r,p If you’re referring to your own property ‘id’ on the node: MATCH (p:Person {id:1}) OPTIONAL MATCH (p)-[r]-() //drops p’s relations DELETE r,p
The simplest way to get all relationships for a single node is like this: MATCH (:User {username: ‘user6’})-[r]-() RETURN r
When using MERGE on full patterns, the behavior is that either the whole pattern matches, or the whole pattern is created. MERGE will not partially use existing patterns — it’s all or nothing. If partial matches are needed, this can be accomplished by splitting a pattern up into multiple MERGE clauses. http://docs.neo4j.org/chunked/stable/query-merge.html MERGE (n)-[:know {r:’123′}]->(test2 {name:’2′}) will … Read more
Yes, you can do something like: match (gal:Person{name:”Yoav”})-[:liked|:watched|:other]->(movie:Movie) return movie Take a look in the docs: Match on multiple relationship types EDIT: From the comments: I need “and” between the relation types.. you gave me an “or” In this case, you can do: match (Yoav:Person{name:”Yoav”})-[:liked]->(movie:Movie), (Yoav)-[:watched]->(movie), (Yoav)-[:other]->(movie) return movie
No, there isn’t. All relationships in neo4j have a direction, starting and ending at a given node. There are a small number of workarounds. Firstly, as you’ve suggested, we can either have two relationships, one going from A to B and the other from B to A. Alternatively, when writing our MATCH query, we can … Read more
As Michael Hunger mentioned MATCH (n) WHERE NOT EXISTS(n.foo) RETURN n On older versions of Neo4j you can use HAS: # Causes error with later versions of Neo4j MATCH (n) WHERE NOT HAS(n.foo) RETURN n
There is a difference: comma separated matches are actually considered part of the same pattern. So for instance the guarantee that each relationship appears only once in resulting path is upheld here. Separate MATCHes are separate operations whose paths don’t form a single patterns and which don’t have these guarantees.
Yes, by using case insensitive regular expressions: WHERE m.name =~ ‘(?i)neo’ https://neo4j.com/docs/cypher-manual/current/clauses/where/#case-insensitive-regular-expressions
If anything breaks at number like 33, it means that there was a restriction upto 32, why 32? 2^5. It’s not trivial that most of the restrictions are in a factor of 2, MongoDB document size cannot be more than 16 MB, on a collection there could be maximum index, no more than 64. etc. … Read more
You may also want to try a cypher query such as: START n=node(*) RETURN n; It’s very obvious, and it will return all the existing nodes in the database. EDIT : the following displays the nodes and the relationships : START n=node(*) MATCH (n)-[r]->(m) RETURN n,r,m;