What with clause do? Neo4j

Question

I don't understand what WITH clause do in Neo4j. I read the The Neo4j Manual v2.2.2 but it is not quite clear about WITH clause. There are not many examples. For example I have the following graph where the blue nodes are football teams and the yellow ones are their stadiums.

I want to find stadiums where two or more teams play. I found that query and it works.

match (n:Team) -[r1:PLAYS]->(a:Stadium)
with a, count(*) as foaf
where foaf > 1
return a

count(*) says us the numbers of matching rows. But I don't understand what WITH clause do.

Answer 1

WITH allows you to pass on data from one part of the query to the next. Whatever you list in WITH will be available in the next query part.

You can use aggregation, SKIP, LIMIT, ORDER BY with WITH much like in RETURN. The only difference is that your expressions have to get an alias with AS alias to be able to access them in later query parts.

That means you can chain query parts where one computes some data and the next query part can use that computed data. In your case it is what GROUP BY and HAVING would be in SQL but WITH is much more powerful than that.

here is another example

match (n:Team) -[r1:PLAYS]->(a:Stadium)
with distinct a 
order by a.name limit 10
match (a)-[:IN_CITY]->(c:City)
return c.name