Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

TypeError: Cannot read property '2' of null

See original GitHub issue

What you are doing?

Creating a record with the same value in a column that is Unique:true. I’m using FeathersJS with uses Sequelize. I successfully inserted new record via restful api using Postman. However if I send the same request again( create a user with the same email which the column is unique) it crashes the server with error “TypeError: Cannot read property ‘2’ of null”.

Below is the model I am using

// code here
const Sequelize = require('sequelize');

module.exports = function(sequelize) {
  const user = sequelize.define('users', {
    email: {
      type: Sequelize.STRING,
      allowNull: false,
      unique: true
    },
    password: {
      type: Sequelize.STRING,
      allowNull: false
    }
  }, {
    freezeTableName: true
  });

What do you expect to happen?

I expected to get a response back with an error stating its a duplicate or at least a clean error.

What is actually happening?

Crashed server since error wasn’t caught.

Output, either JSON or SQL

Dialect: mysql Database version: 5.7.13 Sequelize version: 3.24.4

Issue Analytics

State:
Created 7 years ago
Comments:15 (8 by maintainers)

Top GitHub Comments

3reactions

akhourycommented, Apr 21, 2018

The issue is here:

https://github.com/sequelize/sequelize/blob/f8a98a145443c890be9cab4c941abda28845e4c0/lib/dialects/mysql/query.js#L199-L212

I put a log statement to see the err and it looks like this.

{
  "code": "ER_DUP_ENTRY",
  "errno": 1062,
  "sqlState": "23000",
  "sqlMessage": "",
  "sql": "INSERT INTO `users` (`id`,`email`,`password`,`createdAt`,`updatedAt`) VALUES (DEFAULT,'xxxxx@gmail.com','$2a$10$0yoLkp7LQD.IcHFfNCib..hL8LeM/soCUdSuOF1c1.NGHjeF8nNbO','2018-04-21 08:52:42','2018-04-21 08:52:42');"
}

There is no err.message so match is null, and there are 2 statements that don’t guard against it.

        const uniqueKey = this.model && this.model.uniqueKeys[match[2]];

and

          fields[match[2]] = match[1];

I am using MySQL 5.7.21

1reaction

akhourycommented, Apr 20, 2018

this is till happening when I try to update a record with a column (that is set to unique:true) with a non unique value,

sequelize v4.28.6
node v9.2.0
mysql 5.7.21

/Users/user/code/backend/node_modules/sequelize/lib/dialects/mysql/query.js:186
        const uniqueKey = this.model && this.model.uniqueKeys[match[2]];
                                                                   ^

TypeError: Cannot read property '2' of null
    at Query.formatError (/Users/user/code/backend/node_modules/sequelize/lib/dialects/mysql/query.js:186:68)
    at Query.connection.query [as onResult] (/Users/user/code/backend/node_modules/sequelize/lib/dialects/mysql/query.js:55:23)
    at Query.Command.execute (/Users/user/code/backend/node_modules/mysql2/lib/commands/command.js:30:12)
    at Connection.handlePacket (/Users/user/code/backend/node_modules/mysql2/lib/connection.js:515:28)
    at PacketParser.onPacket (/Users/user/code/backend/node_modules/mysql2/lib/connection.js:94:16)
    at PacketParser.executeStart (/Users/user/code/backend/node_modules/mysql2/lib/packet_parser.js:77:14)
    at Socket.<anonymous> (/Users/user/code/backend/node_modules/mysql2/lib/connection.js:102:29)
    at Socket.emit (events.js:159:13)
    at addChunk (_stream_readable.js:265:12)
    at readableAddChunk (_stream_readable.js:252:11)
    at Socket.Readable.push (_stream_readable.js:209:10)
    at TCP.onread (net.js:598:20)