如何显示neo4j中的关系

Question

I've attached the sample input comma separated value file and a hand drawn image showing my expected output down below.

Problem Description:
--------------------

I have a CSV file containing a list of nodes where each line denotes a relationship of node at line[0] with every other list of nodes line[2],line[2],line[3].....line[4500] in that line

Ex. Sample Input File:

0,1,2,3 (line 1)  
1,2 (line 2)    
2,4 (line 3)  
3,7,19 (line 4)  
10,4,5,11 (line 5)

Please note (line 1),(line 2) etc. is not present in actual CSV file. Here I've named them just for sake of explanation.

for line 1 (Let 'line') node at 
line[0] i.e. "0" has a directed "friends" relationship with 
nodes at line[2] i.e "1" 
nodes at line[4], i,e."2"
nodes at line[6], i,e."3"

similarly again for line 2 (Let 'line') node at 
line[0] i.e. "1" has a directed "friends" relationship with 
nodes at line[2] i.e "2" 

similarly again for line 3(Let 'line')  node at 
line[0] i.e. "2" has a directed "friends" relationship with 
nodes at line[2] i.e "4" 


similarly again for line 4(Let 'line')  node at 
line[0] i.e. "3" has a directed "friends" relationship with 
nodes at line[2] i.e "7" 
nodes at line[4], i,e."19"

and so on....

what i am trying to do is I want to show a graph in Neo4j depicting the suggested friend relationship among each nodes.

what I cannot figure out is how to iterate the whole csv file as well as capture the relationship among each nodes on each line of csv file.

Please Note:[I have attached the expected hand drawn output of a sample input file.]

Link to Comma separated value file containing the friends

Link to Image

Answer 1

First, save your CSV file into Neo4j import directory (take a look in Neo4j files location docs ). After, use Neo4j LOAD CSV statement to import your data. The script I used to reproduce your desired output is as follow:

// Load the csv file
load csv from "file:///friends.csv" as line
// calculate the indexes from the second column to the last
with line, range(1, size(line) - 1) as indexes
// merge (create or assign) the node from first column (0,1,2,3,10)
merge(a:Node{id:line[0]})
// pass 'a', 'indexes' and 'line' to the next context
with a, indexes, line
// unwind the indexes into single index per row
unwind indexes as index
// merge (create or assign) the node from other columns
merge(b:Node{id:line[index]})
// merge the relationship between a and b
merge(a)-[:FRIEND_OF]->(b)

The output considering your sample CSV file will be: