cypher: how to get both my tags AND my friends' tags

[arikan]

Trying to get both my tags AND my friends' tags in a single query...

find my friends' tags whose name is "bla":

q = Neo4j._query("START me=node(1) MATCH me-[:`following`]->friend-[:`User#tags`]->tag WHERE tag.name = 'bla' RETURN tag ORDER BY tag.name")

find my and friends' shared tags (intersection) whose name is "bla":

q = Neo4j._query("START me=node(1) MATCH me-[:`User#tags`]->tag, me-[:`following`]->friend-[:`User#tags`]->tag WHERE tag.name = 'bla' RETURN tag ORDER BY tag.name")

How can I get both my tags AND my friends' tags (union)? Couldn't see any way to combine MATCH in Cypher, any help appreciated.

Thanks,

Burak

[Michael Hunger]

What do you actually want to do?

you can use two different tags here:

q = Neo4j._query("START me=node(1) MATCH me-[:`User#tags`]->tag1, me-[:`following`]->friend-[:`User#tags`]->tag1 WHERE tag1.name = 'bla' and tag2.name = 'bla' RETURN tag1,tag2 ORDER BY tag.name")

you can also use collect to take the friends tags first and then add yours secondly

START me=node(1) MATCH me-[:`following`]->friend-[:`User#tags`]->tag WHERE tag.name = 'bla'

with me, tag

order by tag.name

with me, collect(tag) as tags

MATCH me-[:`User#tags`]->tag

return tags + collect(tag)

you can use paths as expressions, then they return just a collection of paths

return extract(p in me-[:`User#tags`]->() : last(p)) as my_tags

or 

extract(p in friend-[:`User#tags`]->() : last(p)) as friend_tags

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[arikan]

Thanks Michael, I tried the following based on your example, but got an error:

START me=node(1) MATCH me-[:`following`]->friend-[:`User#tags`]->tag WHERE tag.name =~ '(?i)bla.*'

WITH me, tag

ORDER BY tag.name

WITH me, collect(tag) as tags

MATCH me-[:`User#tags`]->tag WHERE tag.name =~ '(?i)bla.*'

RETURN tags + collect(tag)

Java::OrgNeo4jCypher::SyntaxException: Unknown identifier `tags`.

[Michael Hunger]

Which version are you using?

There was an issue with that that was recently fixed (1.9.M04 I think)

[arikan]

I an currently on neo4j 1.8.1

basically trying to search the combination of tags by me and by my friends in a single query.