Statistic people base on role and status

Question

I'm now making an application uses neo4j as my database. I have one class:

class Person
{
  public string Id{get;set;}
  public int Role{get;set;}
  public int Status {get;set;}
}

Now I have 50 nodes, 25 of them are :

{
  Id : <GUID>
  Role: 3,
  Status : 0
}

And the other 25 are :

{
  Id: <GUID>
  Role: 3,
  Status : 2
}

I want to statistic the people base on their role and status. With those records above, I have:

25 people have role 3 and status is 0

25 people have role 3 and status is 2

I've tried this query :

MATCH (a:Person), (b:Person)
WHERE (a.Status = 0 AND a.Role = 3) OR (b.Status = 2 AND b.Role = 3)
RETURN COUNT(a), COUNT(b)

Instead of 25, 25.

It gave me : 6976, 6976

I don't know what the problem is.

Can anyone help me please ? Thank you.

P/S: I'm using graphenedb.

Answer 1

Your statement builds a cross product of all person in your graph.

Try this instead

MATCH (p:Person)
RETURN p.Role, p.Status, count(*)

In Cypher there's no "group by". If you use an aggregation function like count aggregation is done automatically on the other expressions (here p.Role and p.Status).