sequelize .create is not a function error

You cannot reach a variable from a file, by only requiring it in another one. You need to either define an object literal to hold all your variables in one place and assign it to module.exports, or you need to import them from different files separately.

In your case, I would create separate files to hold table schemas, and then import them by sequelize.import under one file, then require that file.

Like this:

models/index.js:

var sequelize = new Sequelize('DBNAME', 'root', 'root', { 
  host: "localhost",           
  dialect: 'sqlite',           

  pool:{
    max: 5, 
    min: 0,
    idle: 10000                
  },

  storage: "SOME_DB_PATH"
}); 

// load models                 
var models = [                 
  'Users',            
];
models.forEach(function(model) {
  module.exports[model] = sequelize.import(__dirname + '/' + model);
});

models/Users.js

var Sequelize = require("sequelize");

module.exports=function(sequelize, DataTypes){ 
  return Users = sequelize.define("Users", {
    id: {
      type: DataTypes.INTEGER, 
      field: "id",             
      autoIncrement: !0,       
      primaryKey: !0
    },
    firstName: {               
      type: DataTypes.STRING,  
      field: "first_name"      
    },
    lastName: {                
      type: DataTypes.STRING,  
      field: "last_name"       
    },
  }, {
    freezeTableName: true, // Model tableName will be the same as the model name
    classMethods:{

      }
    },
    instanceMethods:{

      }
    }
  });
};

Then import each model like this:

var Users = require("MODELS_FOLDER_PATH").Users;

Hope this helps.

Just use

const { User } = require("../models");

Update :

in newer version of sequelize v6 and beyond sequelize.import is deprecated

sequelize docs recommend using require now

If you have generated models using migrations

this is how your model file will look like

models/user.js

'use strict'
module.exports = (sequelize, DataTypes, Model) => {
    class User extends Model {
        /**
         * Helper method for defining associations.
         * This method is not a part of Sequelize lifecycle.
         * The `models/index` file will call this method automatically.
         */
        static associate(models) {
            // define association here
        }
    };
    User.init({
        name: {
            type: DataTypes.STRING,
            allowNull: false
        },
        phone_number: {
            type: DataTypes.STRING(20)
        },
        otp: {
            type: DataTypes.INTEGER(4).UNSIGNED
        },{
        sequelize,
        modelName: 'User',
    });
    return User;
};

as you can see your model export function has sequelize DataTypes & Model parameters.

so when you import this model you should send above arguments.

Example

I am importing user model in controllers/user.js file, it could be any file

controllers/controller.js

const Sequelize = require('sequelize');
const sequelize = require('../config/db').sequelize;

// Bring in Model
const User = require('../models/user')(sequelize, Sequelize.DataTypes,
     Sequelize.Model);
// your code...
// User.create(), User.find() whatever

Notice that sequelize(with small 's') and Sequelize(with capital 'S') are different things, first one represent instance of Sequelize created using new Sequelize, second one is just package you installed & imported

first one (sequelize) can be found wherever you started a connection to database using const sequelize = new Sequelize() usually from app.js or db.js file, make sure to export it from there and import it into where you want to use Model i.e controller

export sequelize instance

db.js Or app.js

const sequelize = new Sequelize();
... //your code
...
module.exports = {
sequelize: sequelize
}