Change default column name sequelize

I am working with Nodejs, Sequelize . This is the following structure for my user model:

"use strict";

module.exports = function(sequelize, DataTypes) {
  var User = sequelize.define('user', { 
    first_name: {
      type: DataTypes.STRING,
      allowNull: false,
    },
    last_name: {
      type: DataTypes.STRING,
      allowNull: false,
    },
    email: {
      type: DataTypes.STRING,
      allowNull: false,
      unique: true,
      validate: {
        isUnique: function (email, done) {
            User.find({ where: { email: email }})
                .done(function (err, user) {
                    if (err) {
                        done(err);
                    }
                    if (user) {
                        done(new Error('Email already registered'));
                    }
                    done();
                });
        }
    }
    },
    profile_image_path: {
      type: DataTypes.STRING,
      allowNull: true,
    },
    active_flag: {
      type: DataTypes.BOOLEAN,
      allowNull: true,
      defaultValue: true
    },
    delete_flag: {
      type: DataTypes.BOOLEAN,
      allowNull: true,
      defaultValue: false
    }
  }, {
    classMethods: {
      associate: function(models) {
        User.hasMany(models.account),
        User.hasMany(models.user_has_contact)
      }
    }
  });
  return User;
};

      

        
        
        
      

    

By default, 3 columns are created:

• ID
• createdAt
• updatedAt

I do not want createdAt

and updatedAt

in this format, I want created_at

and updated_at

. How do I change this default column name ???

I have another table user_has_contact

with the following ratio:

{
    classMethods: {
      associate: function(models) {
        UserHasContact.belongsTo(models.user)
      }
    }
  }

      

        
        
        
      

    

Automatically creates a field userId

, but again I want it to be user_id

. Any suggestion would be appreciated!