CODEWITHSUNDEEP
javascriptnode.jsneo4j
mfontaine
mfontaine

Reputation: 75

Neo4J - Nodes not creating when connecting through JavaScript

I am trying to add a node to a neo4j database in a node.js app and the code seems to execute fine, but no node is created.

Here is my code: 

var neo4j = require('neo4j-driver');

// the rest of my program 

const driver = new neo4j.driver(
  "bolt://localhost:7687",
  neo4j.auth.basic(neouser, neopass)
);
const session = driver.session();
var cypher =
  "MERGE (b:TRIGGER {name:'" +
  rname +
  "'}) MERGE (c:FIELD{name:'" +
  trigger +
  "'}) MERGE (b)<-[:ACTIVATES]-(c)";
try {
  const result = session.run(cypher);
  console.log(result);
} finally {
  console.log("finally");
  session.close();
}
driver.close();

and the Error result: 

Result {
_stack: '\n' +
'    at captureStacktrace (C:\\NGToolbox\\NGToolBox\\node_modules\\neo4j-driver\\lib\\result.js:263:15)\n' +
'    at new Result (C:\\NGToolbox\\NGToolBox\\node_modules\\neo4j-driver\\lib\\result.js:68:19)\n' +
'    at Session._run (C:\\NGToolbox\\NGToolBox\\node_modules\\neo4j-driver\\lib\\session.js:174:14)\n' +
'    at Session.run (C:\\NGToolbox\\NGToolBox\\node_modules\\neo4j-driver\\lib\\session.js:135:19)\n' +
'    at C:\\NGToolbox\\NGToolBox\\routes\\bizrulevis.js:261:30\n' +
'    at Layer.handle [as handle_request] (C:\\NGToolbox\\NGToolBox\\node_modules\\express\\lib\\router\\layer.js:95:5)\n' +
'    at next (C:\\NGToolbox\\NGToolBox\\node_modules\\express\\lib\\router\\route.js:137:13)\n' +
'    at Route.dispatch (C:\\NGToolbox\\NGToolBox\\node_modules\\express\\lib\\router\\route.js:112:3)\n' +
'    at Layer.handle [as handle_request] (C:\\NGToolbox\\NGToolBox\\node_modules\\express\\lib\\router\\layer.js:95:5)\n' +
'    at C:\\NGToolbox\\NGToolBox\\node_modules\\express\\lib\\router\\index.js:281:22',
  _streamObserverPromise: Promise { <pending> },
  _p: null,
  _query: "MERGE (b:TRIGGER {name:'DELETEME.1'}) MERGE (c:FIELD{name:'4001'}) MERGE (b)<-[:ACTIVATES]-(c)",
  _parameters: {},
  _connectionHolder: ConnectionHolder {
    _mode: 'WRITE',
    _database: '',
    _bookmark: Bookmark { _values: [] },
    _connectionProvider: DirectConnectionProvider {
      _id: 3,
      _config: [Object],
      _log: [NoOpLogger],
      _userAgent: 'neo4j-javascript/0.0.0-dev',
      _authToken: [Object],
      _connectionPool: [Pool],
      _openConnections: [Object],
      _address: [ServerAddress]
    },
    _referenceCount: 1,
    _connectionPromise: Promise { <pending> }
  }
}
finally

When I go into Neo4j the db is still empty.

I have confirmed that it is active, that I can use that same cypher to create a node, that the connection is being established in the security log and it is not failing due to un/pw. Everything looks perfect, except for the whole nothing created issue.

Thank you for any advice.

edit: added the driver call and the driver close from outside the snippets scope.

Upvotes: 0

Views: 239

Answers (2)

user10453267
user10453267

Reputation:

If you are writing some API, try to use an OGM https://www.npmjs.com/package/neo4j-node-ogm

class SomeModel extends from Model {} //see documentation

and to persist

const a = new SomeModel()
await a.save()

Tell me if that helps you.

Upvotes: 0

cybersam
cybersam

Reputation: 66927

This code should work for you (assuming neouser, neopass, rname, and trigger are defined):

const neo4j = require('neo4j-driver');

async function doIt() {
  const driver = neo4j.driver(
    "bolt://localhost",
    neo4j.auth.basic(neouser, neopass)
  );
  const session = driver.session();

  try {
    await session.writeTransaction(async txc => {
      var result = await txc.run(
        `MERGE (b:TRIGGER {name: $rname})
         MERGE (c:FIELD {name: $trigger})
         MERGE (b)<-[:ACTIVATES]-(c)
         RETURN b, c`,
        {rname: rname, trigger: trigger}
      )

      result.records.map(record => {
          console.log(`b: ${record.get('b')}, c: ${record.get('c')}`);
      })
    })
  } finally {
    console.log("finally");
    await session.close();
    await driver.close();
  }
}

doIt();

This code is aware of the asynchronous nature of the processing, uses the result after the transaction has completed, and only then closes the session and driver. It also uses a writeTransaction to write to the DB.

You should study the driver's github documentation to get an idea of all the ways the driver can be used.

Upvotes: 1

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