CODEWITHSUNDEEP
neo4jcypher
Aviv Paz
Aviv Paz

Reputation: 1125

Neo4j - Delete 2 related nodes with all of their relationships

I'm trying to deletes 2 related nodes with all of their relationship.

This is the query that I've been trying to do that:

match  (picture:Picture) where picture.id='101531146106623881437036830' 
optional match ()-[r]- picture-[:UPLOADED_TO]-(facebook:Facebook)-[rf]-()     
with r,rf,picture,facebook,picture.id as id     
delete r,rf,picture,facebook
return id

Can't seem to get it right for some reason.

Upvotes: 2

Views: 57

Answers (2)

Supamiu
Supamiu

Reputation: 8731

Your query is not working because you can't delete picture, a relation is still linked to it.

Let's check the query and explain the error

match  (picture:Picture) where picture.id='101531146106623881437036830'

Ok you match the picture node, everything is fine here

optional match ()-[r]- picture-[:UPLOADED_TO]-(facebook:Facebook)-[rf]-()

Using optional match is a choice, but the problem here is that you didn't set a variable for UPLOADED_TO, so this relation is seen by the query, but no references are made.

with r,rf,picture,facebook,picture.id as id

Here you push your references to the delete part (it's not needed in fact, only usefull pour aliases here)

delete r,rf,picture,facebook
return id

And finally you delete what you wanted to delete, but here you get an error "Can't delete node because it has relationships" or something like that. It's because UPLOADED_TO relation still exists.

How to fix?

Simply add a reference to UPLOADED_TOrelation to delete it.

match  (picture:Picture) where picture.id='101531146106623881437036830' 
optional match ()-[r]- picture-[r2:UPLOADED_TO]-(facebook:Facebook)-[rf]-()     
with r2,r,rf,picture,facebook,picture.id as id     
delete r2,r,rf,picture,facebook
return id

MicTech's answer should work too, but I wanted to clarify your mistake to avoid doing it again ;)

Upvotes: 2

MicTech
MicTech

Reputation: 45003

What about this

MATCH ()-[r]-(p:Picture {id:'101531146106623881437036830'})-[:UPLOADED_TO]-(fb:Facebook)-[rf]-()
DELETE r, p, fb, r

Upvotes: 2

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