Create a node for each column only once while importing csv into Neo4j - csv

Question

I have a csv file that looks the following way:
I want to create a database from it in Neo4j. Rows are nodes with labels gene, columns are also nodes with labels cell. I need to write a CREATE query that would create all my gene and cell - nodes and a relationship one for each combination of gene and cell. Currently I am stuck with the following code:
LOAD CSV WITH HEADERS FROM 'file:///merged_full.csv' AS line
CREATE (:Gene {id: line.gene_ids, name: line.wikigene_name})
I need to somehow iterate over all columns - starting from index 3 - after creating gene nodes, but I do not know how to do that.

Answer 1

Here are 3 queries that, performed in order, should do what you want.
This query creates a temporary Headers node with a names property that contains the collection of headers from the CSV file. It uses LIMIT 1 to only process the first row of the file. It also creates all the Cell nodes, each with it own name property.
LOAD CSV FROM 'file:///merged_full.csv' AS line
MERGE (h:Headers)
SET h.names = line
WITH line
LIMIT 1
UNWIND line[3..] AS name
MERGE (c:Cell {name: name})
This query uses the APOC function apoc.map.fromNodes to generate a map named cells, which maps each cell name to its cell node. It also gets the Headers node. It then loads the non-header data from the CSV file (using SKIP 1 to skip over the header row), and processes each row as follows. It uses MERGE to get/create a Gene node, g, with the desired id and name. It uses the REDUCE function to generate a collection of the Cell nodes that have a "1" column value in the current row, and the FOREACH clause then creates a (g)-[:HAS]->(x) relationship (if necessary) for every cell, x, in that collection.
WITH apoc.map.fromNodes('Cell', 'name') AS cells
MATCH (h:Headers)
LOAD CSV FROM 'file:///merged_full.csv' AS line
WITH h, cells, line
SKIP 1
MERGE (g:Gene {id: line[1], name: line[2]})
FOREACH(
x IN REDUCE(s = [], i IN RANGE(3, SIZE(line)-1) |
CASE line[i] WHEN "1" THEN s + cells[h.names[i]] ELSE s END) |
MERGE (g)-[:HAS]->(x))
This query just deletes the temporary Headers node (if you wish):
MATCH (h:Headers)
DELETE h;

Answer 2

If the columns correspond with cell nodes, then you should know all the cell nodes you need just be looking at the CSV header.
I'd recommend writing a small query just to create each of the cell nodes you need, then create an index or unique constraint on :Cell(id) (or name, or whatever the property is that is meant to identify a :Cell).
At that point the problem becomes getting and processing each relevant column (I assume only the ones with 1 as the value). APOC Procedures may help here.
apoc.map.sortedProperties() can be used to take your line map and give you a list of key/value list pairs, which you can filter down to those where the key begins with 'V', and where the value is 1, then use what's remaining to match on the relevant :Cell node and create the relationship.