AWS, error message meaning when trying to establish connection with RDS

Question

I am new to AWS, may you please help me.

Was following this tutorial: enter tutorial link

Created a RDS and ran this code below in visual studio code:

File name:test.js

var mysql = require('mysql');
var config = require('./config.json');
var pool  = mysql.createPool({
    host     : config.dbhost,
    user     : config.dbuser,
    password : config.dbpassword,
    database : config.dbname
  });
pool.getConnection(function(err, connection) {
  // Use the connection
  connection.query('SELECT emp_name from Employee where emp_id=1', function (error, results, fields) {
    // And done with the connection.
    connection.release();
    // Handle error after the release.
    if (err) throw error;
    else console.log(results[0].emp_name);
    process.exit();
  });
});

However, when i run node test.js , it returned the following error.

(base) zi-jies-mbp:sql zijie$ node test.js /Users/zijie/node_modules/mysql/lib/protocol/Parser.js:437 throw err; // Rethrow non-MySQL errors ^

TypeError: Cannot read property 'query' of undefined at /Users/zijie/Documents/I&E/Silverride/sql/test.js:11:14 at Handshake.onConnect (/Users/zijie/node_modules/mysql/lib/Pool.js:58:9) at Handshake. (/Users/zijie/node_modules/mysql/lib/Connection.js:525:10) at Handshake._callback (/Users/zijie/node_modules/mysql/lib/Connection.js:491:16) at Handshake.Sequence.end (/Users/zijie/node_modules/mysql/lib/protocol/sequences/Sequence.js:83:24) at Handshake.ErrorPacket (/Users/zijie/node_modules/mysql/lib/protocol/sequences/Handshake.js:125:8) at Protocol._parsePacket (/Users/zijie/node_modules/mysql/lib/protocol/Protocol.js:291:23) at Parser._parsePacket (/Users/zijie/node_modules/mysql/lib/protocol/Parser.js:433:10) at Parser.write (/Users/zijie/node_modules/mysql/lib/protocol/Parser.js:43:10) at Protocol.write (/Users/zijie/node_modules/mysql/lib/protocol/Protocol.js:38:16)

May you please share and advice me on what is the error about, and how to remedy it? Thanks in Advance.

Juned Ahsan Juned Ahsan · Accepted Answer · 2019-12-17T04:15:41

As per your error

TypeError: Cannot read property 'query' of undefined at

It seems that the connection object is not created. This can be due to combination of things such as

you are not passing the correct parameters for the connection
RDS security group is not allowing the connection (It seems to be an issue faced by multiple people using that tutorial: check comments)

AWS, error message meaning when trying to establish connection with RDS

1 Answers