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Excluding some of the returned MATCH query results in Neo4J

I am using the MATCH query below (refer to book viewers):

MATCH (u:User {id:15})-[r:REVIEW]->(b:Book)
WITH u,b
MATCH (t:User)-[r:REVIEW]->(b)
RETURN distinct t

This cypher first matches the books viewed by the user with id = 15. Then it uses another MATCH command to find any other user who has viewed any book that was checked by the user with id = 15. However, the returned users include the user with id = 15. How can I exclude it?

Note that I used the "detached" command so that I don't get the same user 2 or more times. FE if a user (id = 15) has viewed 2 books and another user has viewed these 2 books, I would get the last user 2 times without the "separate" ones.

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2 answers


Another option is to capture what you want in a single template, for example:

MATCH (u:User{id:15})-[:REVIEW]->(b:Book)<-[:REVIEW]-(t:User)
RETURN distinct t

If you have one suggestion and a MATCH pattern, since we distinguish between variables u

and t

, it will never match t

- u

.



If you want to use a shorthand version (assuming: book nodes are the only things that: Users can: BROWSE and that: users are only the types of nodes that can: BROWSE: Books), then you can shorten that to

MATCH (u:User{id:15})-[:REVIEW*2]-(t:User)
RETURN distinct t
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You just need to add a where clause on the second match, which excludes users that are the same as the first user that was matched.



MATCH (u:User{id:15})-[r:REVIEW]->(b:Book)
with u,b
MATCH (t:User)-[r:REVIEW]->(b)
WHERE t <> u
RETURN distinct t
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