CODEWITHSUNDEEP
csvneo4jterminalcyphercypher-shell
roschach
roschach

Reputation: 9336

How to run a cypher script file from Terminal with the cypher-shell neo4j command?

I have a cypher script file and I would like to run it directly.

All answers I could find on SO to the best of my knowledge use the command neo4j-shell which in my version (Neo4j server 3.5.5) seems to be deprecated and substituted with the command cyphershell.

Using the command sudo ./neo4j-community-3.5.5/bin/cypher-shell --help I got the following instructions.

usage: cypher-shell [-h] [-a ADDRESS] [-u USERNAME] [-p PASSWORD] [--encryption {true,false}] [--format {auto,verbose,plain}] [--debug] [--non-interactive] [--sample-rows SAMPLE-ROWS] [--wrap {true,false}] [-v] [--driver-version] [--fail-fast | --fail-at-end] [cypher]

A command line shell where you can execute Cypher against an instance of Neo4j. By default the shell is interactive but you can use it for scripting by passing cypher directly on the command line or by piping a file with cypher statements (requires Powershell on Windows).

My file is the following which tries to create a graph from csv files and it comes from the book "Graph Algorithms".

WITH "https://github.com/neo4j-graph-analytics/book/raw/master/data" AS base 
WITH base + "transport-nodes.csv" AS uri
LOAD CSV WITH HEADERS FROM uri AS row
MERGE (place:Place {id:row.id})
SET place.latitude = toFloat(row.latitude),
  place.longitude = toFloat(row.latitude),
  place.population = toInteger(row.population)

WITH "https://github.com/neo4j-graph-analytics/book/raw/master/data/" AS base 
WITH base + "transport-relationships.csv" AS uri
LOAD CSV WITH HEADERS FROM uri AS row
MATCH (origin:Place {id: row.src})
MATCH (destination:Place {id: row.dst})
MERGE (origin)-[:EROAD {distance: toInteger(row.cost)}]->(destination)

When I try to pass the file directly with the command:

sudo ./neo4j-community-3.5.5/bin/cypher-shell neo_4.cypher

first it asks for username and password but after typing the correct password (the wrong password results in the error The client is unauthorized due to authentication failure.) I get the error:

Invalid input 'n': expected <init> (line 1, column 1 (offset: 0))
"neo_4.cypher"
 ^

When I try piping with the command:

 sudo cat neo_4.cypher| sudo ./neo4j-community-3.5.5/bin/cypher-shell -u usr -p 'pwd'

no output is generated and no graph either.

How to run a cypher script file with the neo4j command cypher-shell?

Upvotes: 10

Views: 16618

Answers (3)

TFuto
TFuto

Reputation: 1462

Use cypher-shell -f yourscriptname. Check with --help for more description.

Upvotes: 12

roschach
roschach

Reputation: 9336

The problem is in the cypher file: each line should end with a semicolon: ;. I still need sudo to run the program.

The file taken from the book seems to contain other errors as well actually.

Upvotes: 3

GMc
GMc

Reputation: 1774

I think the key is here:

cypher-shell -- help

... Stuff deleted

positional arguments:
  cypher                 an optional string of cypher to execute and then exit

This means that the paremeter is actual cypher code, not a file name. Thus, this works:

GMc@linux-ihon:~> cypher-shell "match(n) return n;"
username: neo4j
password: ****
+-----------------------------+
| n                           |
+-----------------------------+
| (:Job {jobName: "Job01"})   |
| (:Job {jobName: "Job02"})   |

But this doesn't (because the text "neo_4.cypher" isn't a valid cypher query)

cypher-shell neo_4.cypher

The help also says:

example of piping a file:
  cat some-cypher.txt | cypher-shell

So:

cat neo_4.cypher | cypher-shell

should work. Possibly your problem is all of the sudo's. Specifically the cat ... | sudo cypher-shell. It is possible that sudo is protecting cypher-shell from some arbitrary input (although it doesn't seem to do so on my system).

If you really need to use sudo to run cypher, try using the following:

sudo cypher-shell arguments_as_needed < neo_4.cypher

Oh, also, your script doesn't have a return, so it probably won't display any data, but you should still see the summary reports of records loaded.

Perhaps try something simpler first such as a simple match ... return ... query in your script.

Oh, and don't forget to terminate the cypher query with a semi-colon!

Upvotes: 5

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