Query not returning any results

[leelandclay]

Hi,
I have :Person, :Question, and :Answer nodes. A person can either answer a question or skip it. If they answer the question, I'm adding a relationship (:ANSWERED) between the :Person node and the :Answer node. If they decide to skip it, I'm adding a relationship (:SKIPPED) between the :Person node and the :Question node. I need to find a :Question that hasn't been answered or skipped to present to the user. Right now, I'm just trying to find the ones that haven't been skipped. This is my query:

MATCH (p:Person {firstName: 'Leeland'})-[r]->(q:Question)
WHERE r IS NULL
RETURN q

I found some SO answers that claim this should work...but they're from version 2.2 (so...a bit old). I also tried using it with an OPTIONAL match...that didn't work either. It returned null.

MATCH (p:Person {firstName: 'Leeland'})
OPTIONAL MATCH (p)-[r]->(q:Question)
WHERE r IS NULL
RETURN q

I have the :Person node and two :Question nodes created. I also put a :SKIPPED relationship between the :Person and :Question node.

Any thoughts on what I'm doing wrong?

[leelandclay]

Update. I found another post that showed another way of writing the query and I tried it. This shows the non-skipped question. Now to work on filtering out the answered ones...

MATCH (q:Question)
WHERE NOT (q)-[:SKIPPED]-(:Person {firstName: 'Leeland'})
RETURN DISTINCT q

[leelandclay · Accepted solution]

OK...I feel silly now. I stared at this problem for almost 3 hours before I posted the question. I went to dinner, came back and posted the question and found the answers myself. The following query is providing the results I need.

MATCH (q:Question)
WHERE NOT (q)-[*]-(:Person {firstName: 'Leeland'})
RETURN DISTINCT q

Thanks for reading 🙂