Hello, I would like to suggest that in the next version of APOC a new function could be implemented which checks, if a certain node with a specific value in a property exists or not. For example: apoc.node.exist(u:User {user_email: "abc@xyz.at"}) The result could be a very simple TRUE / FALSE. T…

Why not just use cypher matching? Or existential subqueries? WHERE exists { MATCH (u:User {user_email: "abc@xyz.at"}) }

Thank you Michael, two users of the community (I don't know how to mention them here) have already found a solution in another thread (I don't know how to link there).

It was in this thread: [image] Check if node exists and use the result as a condition Cypher I added a suggestion to the documentation for OPTIONAL MATCH. This is a great example! I've learned a lot! Thanks for showing us OPTIONAL MATCH. I hadn't quite appreciated wha…

I think it's a little trickier than that. This does NOT work (although it seems like it should): RETURN exists (MATCH (u:User {name: "abc@xyz.at"})) Invalid input ')': expected whitespace or a relationship pattern (line 1, column 55 (offset: 54)) "RETURN exists (MATCH (u:User {name: "abc@xyz.at…

Michael, could you please outline the difference between exists() and exists {}? THX, JJJ

exits() is a predicate function, which might be deprecated at some point. And exists {} is more like a structural clause, also called existential subquery, so like a subquery but one that only returns false/true on zero/non-zero results of the query (which currently can contain match/where) …

@michael.hunger Unfortunately, I'm at the stage of where Cypher is like Legos: I can build fragments but I can't always build an entire structure that I want. I'm beginning to understand subqueries (which I believe don't get enough emphasis) but I'm not fully there... I don't understand why I'm …

Hi, Just tried this and it didn't work. Got the following error: Invalid input 'WHERE': expected "RETURN" "CREATE" "DELETE" "SET" "REMOVE" "DETACH" "MATCH" "WITH" "UNWIND" "USE" "CALL" "LOAD" "FROM" "FOREACH" "MERGE" "OPTIONAL" "USING" (line 1, column 1 (offset:…

Perhaps you need 4.3 for that but I thought it would work in 4.2 already just tried this on 4.3 WITH 1 as x WHERE exists { MATCH (u:Client{code:"12"}) } RETURN *

Check if node exists - proposal for a new APOC-function

Neo4j Graph Platform Procedures & APOC

clem (Clem) January 16, 2021, 5:41pm 4

It was in this thread:

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Check if node exists - proposal for a new APOC-function

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