Sequelize + Typescript build error. pg-native and not a constructor.

What you are doing?

Basically trying to build a typescript code using sequelize and then compiling it using webpack. However, I seem to be getting two different errors:

• I’m required to install pg-native (even though native is set to false).
• If I happen to have pg-native installed, I get:

import Sequelize from 'sequelize';
import {constants} from './../constants.ts';

export var initialized: Boolean = false;

export function initialize():void {
  if(this.initialized){
    return;
  }

  var sequelize = new Sequelize(constants.DATABASE_NAME,constants.DATABASE_USERNAME,constants.DATABASE_PASSWORD,{
    host: constants.DATABASE_HOST,
    dialect: 'postgres',
    native : false,
    pool: {
      maxConnections: 100,
      minConnections: 0,
      maxIdleTime: 10000
    }

  });

  this.initialized = true;
};

I’m just calling the intialize function on my server.js file (which builds and runs just fine if I omit the sequelize functionality)

What do you expect to happen?

I expected it to build and run, as you might expect.

What is actually happening?

I’m getting

ERROR in ./~/pg/lib/native/index.js
Module not found: Error: Cannot resolve module 'pg-native' in /home/luis/Projects/FinalProject-Gamify-Education/node_modules/pg/lib/native
 @ ./~/pg/lib/native/index.js 1:13-33

and, If I manage t install pg-native (which is currently giving away problems to work), I get:

ERROR: new sequelize_1.default is not a constructor. 
which points to the line sequelize = new Sequelize ...

Dialect: postgres Database version: 9.3.13 Sequelize version: 3.23.3

[felixfbecker]

@lrojas94 Sequelize 3 uses module.exports =, so you have to do import Sequlize = require('sequelize') instead of import Sequelize from 'sequelize'. Sequelize 4 will also support the default export.

@mickhansen you can ping me for TypeScript questions in the future, I’m using Seq + TS in production 😃

[lrojas94]

After reading for a while I see your point now @felixfbecker . Thanks a lot! and you too @mickhansen , I’ll be marking this as solved.