Neo4j Recursive function

Question

I am trying to make a tag system using Neo4j Cypher and having a very hard time (spent the last twelve hours banging my head) to making a recursive function.

Let's say an array of property is given.

The recursive function will: 1. first check if the root has a node relationship [:b] with a node that has property 'name' value as the first element in the array.

a. If yes, simply set the root to the next element and check if the next node has property 'name value as the second element in the array

b. Else, create a new node with the property and set that node as the root.

What do you mean by "root" and what does "set the root" mean? Are you simply trying to make sure that the array's elements are turned into linked nodes in the DB? — cybersam, Jun 26 '19 at 02:46

score 0 · Accepted Answer · answered Jun 26 '19 at 03:09

0

This query will make sure that the names in the names parameter (a list of strings) are represented by Name nodes linked together, in order, by b relationships:

MERGE (first:Name {name: $names[0]})
FOREACH(i IN RANGE(1, SIZE($names)-1) |
  MERGE (a:Name {name: $names[i-1]})
  MERGE (c:Name {name: $names[i]})
  MERGE (a)-[:b]->(c)
)

The first MERGE is there so that a names list with only one element will still cause a single node to be created (if necessary).

For example, if the names parameter is ['aa','bb','cc'], then the resulting path will look like this:

answered Jun 26 '19 at 03:09

cybersam

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Wow. Thank you so much. You made my week. Thank you once again. – Tony Kim Jun 26 '19 at 06:03
Is it possible to add another node with a different label (ex. item) and connect it with 'cc' from the above example? – Tony Kim Jun 26 '19 at 15:42
Not clear what you want to do. Maybe create another question with full details. – cybersam Jun 26 '19 at 18:28

Neo4j Recursive function

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