CODEWITHSUNDEEP
node.jsoracle-databasenode-oracledb
user68288
user68288

Reputation: 774

Node.js oracledb module -- TypeError: Cannot read property 'close' of undefined

I am trying to run simple SQL statements using Oracledb npm for Nodejs. This has worked in the past with no issue but suddenly I am getting this error in a different environment. Possibly due to aliases? I am not sure.

The goal of the line causing the issue is to close out the connection once it completes or fails. I found the logic directly in the docs from Oracle found here: http://oracle.github.io/node-oracledb/doc/api.html#connectionclose

Really would appreciate any help!

const oracledb = require('oracledb');
const async = require('async');
const {getAwsSecret} = require('./awssecret');
var alias = "";

async function initialize() {
  // Set Oracle Pool Settings
  let hrPool = {
    poolMin: 10,
    poolMax: 10,
    poolIncrement: 0
  }

  var secret = await getAwsSecret('MAIN');
  const secretJSON = JSON.parse(secret);
  hrPool.user = secretJSON[process.env.CURENV + 'username'];
  hrPool.password = secretJSON[process.env.CURENV + 'password'];
  hrPool.connectString = secretJSON[process.env.CURENV + 'host'] + '/' + secretJSON[process.env.CURENV + 'dbname'];
  hrPool.poolAlias = secretJSON.alias;
  alias = secretJSON.alias;

  try { 
  await oracledb.createPool(hrPool);
  } catch (err) {
    console.log(err);
  }
}

module.exports.initialize = initialize;

async function close() {
  await oracledb.getPool().close();
}

module.exports.close = close;

async function simpleExecute(statement, binds = [],clientdetails = [], opts = {}) {
    let conn;
    opts.outFormat = oracledb.OBJECT;
    opts.autoCommit = true;
    try {
      // Get Connection
      conn = await oracledb.getConnection(alias);
      // Run Query
      const result = await conn.execute(statement, binds, opts);
    ///////////// POST EXECUTION HANDLING /////////////
    if (conn) { // conn assignment worked, need to close
      try {
        // Close Connection
        await conn.close();
        // Return Result
        return result;
      } catch (err) {
        console.log(err);
      }
    }
    ///////////// POST EXECUTION HANDLING /////////////
    } catch (err) {
      await conn.close();

    } 
  }

module.exports.simpleExecute = simpleExecute;

Error:

TypeError: Cannot read property 'close' of undefined 2021-04-23T14:36:51.269-04:00  at 
Object.simpleExecute (/usr/src/app/services/database.js:59:18)

Upvotes: 1

Views: 1137

Answers (1)

Christopher Jones
Christopher Jones

Reputation: 10496

If there is an error getting the connection, your catch block calls conn.close() without having a valid conn. This gives the error you see. It may not be the only cause, but tidying the code will help.

Your conn.close() could be just once in a finally() block. Look at examples like example.js e.g. like:

  let connection;

  try {
    connection = await oracledb.getConnection(dbConfig);

    result = await connection.execute(sql, binds, options);
    console.dir(result, { depth: null });

  } catch (err) {
    console.error(err);
  } finally {
    if (connection) {
      try {
        await connection.close();
      } catch (err) {
        console.error(err);
      }
    }
  }

Some other tips:

  • If you code is going to execute a few statements consecutively then don't do a getConnection()/close() around each. This affects pool scalability because there is some latching on the shared pool resource, and it adds extra code to the whole step.
  • Avoid always committing. This can destroy transactional consistency and add overhead if done unnecessarily.
  • Use an explicit drainTime in the pool.close() call to ensure it is closed, see webapp.js.

Upvotes: 2

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