I have a Cypher request for Neo4J of this kind:
MATCH (u:User {uid: $userId})
UNWIND $contextNames as contextName
MERGE (context:Context {name:contextName.name,by:u.uid,uid:contextName.uid})
ON CREATE SET context.timestamp=$timestamp
MERGE (context)-[by:BY]->(u)
SET by.timestamp = $timestamp
My params are:
{
"userId": "15229100-b20e-11e3-80d3-6150cb20a1b9",
"contextNames": [
{
"uid": "822e2580-1f5e-11e9-9ed0-5b93e8900a78",
"name": "fnas"
}
],
"timestamp": "1912811921129"
}
That query above sets 8 parameters because I have (probably) 8 other relationships of the :BY type in relation to that u. Which seems to me illogical as it should only find one relationship between a concrete context and a concrete u, create it if it doesn't exist, and set the property for it
However, when I do this:
MATCH (u:User {uid: $userId})
UNWIND $contextNames as contextName
MERGE (context:Context {name:contextName.name,by:u.uid,uid:contextName.uid})
ON CREATE SET context.timestamp=$timestamp
MERGE (context)-[:BY{timestamp:$timestamp}]->(u)
It either creates a relationship (if the one with the same timestamp doesn't exist) or it simply doesn't do anything (which seems to be the right behavior).
What is the reason for this discrepancy? A bug in Neo4J?
