Unexpected result using queries with optional relationships

[matias...@brinqa.com]

Hi all,

I'm having a hard time building a query with optional relationship using Neo4j 2.3.2.

My query is something like this:

MATCH 

    (n1:Label1)

WHERE 

    (n1.propertyA = {param1})

OPTIONAL MATCH 

    (n1)<-[r:rel1]-(n2:Label2)

WHERE

    (NOT (n1)<-[r:rel1]-(n2) OR n2.propertyB = {param2})

RETURN

    n1;

My intention is to return all n1 objets that don't have a relationship to n2 or if they have a relationship check for propertyB and filter by that. 

What I'm getting is all the n1 even when rel1 exists and propertyB != {param2}

Anyone sees what's the issue in this query? I can't see it...

Thanks,

Matias.

 

[matias...@brinqa.com]

One more thing to add is that what I was doing for previous versions of Neo4j and it was working (but it's not allowed anymore) is the following:

START

   n1=({node})

MATCH

   n1<-[r?:rel1]-n2

WHERE 

   n1.propertyA = {param1} AND (r is null OR n2.propertyB! = {param2})

RETURN 

  n1;

Thanks,

Matias.

[Max De Marzi Jr.]

The  WHERE gets tied to the OPTIONAL MATCH.

If you want the WHERE to apply to the whole thing you need to end the OPTIONAL with a WITH. 

Something like:

MATCH 

    (n1:Label1)

WHERE 

    (n1.propertyA = {param1})

OPTIONAL MATCH 

    (n1)<-[r:rel1]-(n2:Label2)

WITH n1, r, n2
WHERE

    (r IS NULL OR n2.propertyB = {param2})

RETURN

    n1;