Neo4j - Count distinct nodes

Question

I have this kinds of relationships:

(:User)<-[:MENTIONS]-(:Tweet)-[:ABOUT]->(:Topic)

I would like to count all the users mentioned in the tweets regarding some topic.

With the following query

match (n:Topic)<--(t:Tweet)-[:MENTIONS]->(u:User) 
where n.name='politics'
return distinct count(u)

all I get is the relationships count.

What I would like to get is, instead, the number of users mentioned (without duplicates if a user is mentioned several times). How is that possible?

Answer 1

Try putting distinct inside count function, this way:

match (n:Topic)<-[:ABOUT]-(t:Tweet)-[:MENTIONS]->(u:User) 
where n.name='politics'
return count(distinct u)