How do I check the type of a node in cypher?

Question

I have a graph with three node types: NodeX, NodeY, and NodeZ

I have the this cypher query:

MATCH (x:NodeX)-[*]->(d)  
WHERE x.Name = 'pqr'  
RETURN x,d;

Here (d) may could be either NodeY or NodeZ. I'm looking to handle different nodetypes separately. Something like:

MATCH (x:NodeX)-[*]->(d)  
WHERE x.Name = 'pqr'  
WITH d
CASE WHEN typeof(d)=NodeY THEN {MATCH (y:NodeY)-[*]-(z:NodeZ)}
     WHEN typeof(d)=NodeZ THEN {MATCH (z:NodeZ)-[*]-(y:NodeY)}
RETURN y,z

y and z correspond to d. Is this possible to do so?

Answer 1

Nodes have "labels", not "types" (the latter term only applies to relationships).

To get the labels of a node, you can use the LABELS() function. So, to test if node n has the label Foo, you can do something like this in Cypher:

CASE WHEN 'Foo' IN LABELS(n) THEN ... 

However, the CASE clause cannot contain a MATCH clause.

[EDITED]

In your specific case, something like this query (which assumes that, as you said, the only labels possible for d are NodeY and NodeZ) may work:

MATCH (x:NodeX)-[*]->(d)
WHERE x.Name = 'pqr'  
WITH d, CASE WHEN 'NodeY' IN LABELS(d) THEN 'NodeZ' ELSE 'NodeY' END AS otherLabel
MATCH (d)-[*]-(other)
WHERE otherLabel IN LABELS(other)
RETURN d, other;