CODEWITHSUNDEEP
neo4jgraph-databasesneo4j-ogm
Erik Sapir
Erik Sapir

Reputation: 135

neo4j match nodes and relationships if exists

I am developing a small social network applications and i have the following nodes and relationships in my neo4j graph db:

  1. User nodes
  2. Post nodes. Post node is connected to User node by POSTED_BY relationship and Post node might connected to another Post node by SHARING relationship in case a post shares another post.

I would like to retrieve all posts posted by a specific user and for each post also get the original post in case it is a share (and the publisher of the original post).

I managed to get the required info using optional match but i am new to neo4j and not sure if this is the correct way to go:

match (p:Post)-[r: POSTED_BY]-(publisher:User)
where publisher.userId = {userId}
optional match (p:Post)-[r2: SHARED_POST]-(sharedPost:Post)-[r3: POSTED_BY]-(sharedPostPublisher: User)
return p as post,publisher, sharedPost, sharedPostPublisher

Is this the correct way to retrieve this info or should i use other methods?

Upvotes: 1

Views: 67

Answers (1)

Frank Pavageau
Frank Pavageau

Reputation: 11735

Aside from the lack of direction on the relationships, it looks fine.

The lack of direction is of course slightly less self-explanatory (even if there's an implicit direction, as the User isn't POSTED_BY the Post), but it also changes the semantics of the query: because the SHARED_POST relationship can be traversed in any direction, of course you'll get the original post in case of a share, but you'll also get all shares in case it is an original post. That's not what you said you wanted.

Upvotes: 1

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