Node and relationship creation in Neo4j

Question

I have a data set, which looks like this

Now, as one can see that a single person has multiple skillid, along with this data, i also have a skill_ref table, which has 2 columns(skillid and skillname) so from the image above, i can look and say that last person has multiple skills, Now, i want this data to be put in Neo4j, with person and skillname as node, and a relationship of has_skill. But i dont know how to handle the multiple instances, if i split the skillid , then i will have multiple instances of person name, but this is not what i want, i want something like this

in the graph,the center node is the name of the person and the others have skill name, with the arrows pointing a relation has_skill. I am new to neo4j as well as cypher, any help guys will be highly appreciated.

USING PERIODIC COMMIT 
LOAD CSV WITH HEADERS FROM "file:///people_data.csv" AS line
CREATE (p:Person{id:line.people_uid})
WITH line, p
SET p.firstName = line.first_name,p.lastname=line.last_name
WITH line,split(line.skillid,' ') as skill_ids
UNWIND skill_ids as skill_Id
MERGE (skill:Skill{id:skill_Id})
LOAD CSV WITH HEADERS FROM "file:///skills_ref.csv" AS line
WITH line
MERGE(skill:line.skillid{name:line.skillname})
CREATE (p)-[:HAS_SKILL]->(skill)

InverseFalcon InverseFalcon · Accepted Answer · 2018-02-14T12:02:04

You've got the right idea.

The general approach is to first MERGE (or CREATE) the :Person node, then split() the skillid into a list of skill ids, UNWIND the skill id list into rows, then MERGE the skill for the given id (and make sure you have an index or unique constraint on :Skill(id)), then MERGE (or CREATE) the relationship between the :Person node and the :Skill.

Here's an example, loading from a CSV file:

USING PERIODIC COMMIT 
LOAD CSV WITH HEADERS FROM "file:///your.file.url" AS line
CREATE (p:Person{id:line.people_uid})
WITH line, p
SET p.firstName = line.f_name ... <same for the rest of the properties>
UNWIND split(line.skillid, ' ') as skillId
MERGE (skill:Skill{id:skillId})
CREATE (p)-[:HAS_SKILL]->(skill)

EDIT

Regarding the revised query you're attempting, it's actually better to use separate queries for each csv load, using the first to create the nodes and merge the relationships, and the second just to match/merge to skills and add the skill name:

USING PERIODIC COMMIT 
LOAD CSV WITH HEADERS FROM "file:///people_data.csv" AS line
CREATE (p:Person{id:line.people_uid})
SET p.firstName = line.first_name, p.lastname=line.last_name
WITH line, split(line.skillid, ' ') as skill_ids
UNWIND skill_ids as skill_Id
MERGE (skill:Skill{id:skill_Id})
CREATE (p)-[:HAS_SKILL]->(skill)

Then your next query:

LOAD CSV WITH HEADERS FROM "file:///skills_ref.csv" AS line
MERGE (skill:Skill{id:line.skillid})
SET skill.name = line.skillname

Remember that you should have an a unique constraint created on :Skill(id) and :Person(id) first.

Node and relationship creation in Neo4j

1 Answers