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Chinedu Orie
Chinedu Orie

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How to Add New Fields to Existing Sequelize Migration

Sometimes you realize that you need to add some new fields to an existing sequelize migrations. This is especially important for production apps where refreshing the migration is not an option. Below is a quick guide on how to implement it.

Let's assume you want to add some new fields to Users table; below are the steps.

Step 1 - Create a new migration

npx sequelize-cli migration:create --name modify_users_add_new_fields
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Step 2 - Edit the migrations to suit the need

module.exports = {
  up(queryInterface, Sequelize) {
    return Promise.all([
      queryInterface.addColumn(
        'Users', // table name
        'twitter', // new field name
        {
          type: Sequelize.STRING,
          allowNull: true,
        },
      ),
      queryInterface.addColumn(
        'Users',
        'linkedin',
        {
          type: Sequelize.STRING,
          allowNull: true,
        },
      ),
      queryInterface.addColumn(
        'Users',
        'bio',
        {
          type: Sequelize.TEXT,
          allowNull: true,
        },
      ),
    ]);
  },

  down(queryInterface, Sequelize) {
    // logic for reverting the changes
    return Promise.all([
      queryInterface.removeColumn('Users', 'linkedin'),
      queryInterface.removeColumn('Users', 'twitter'),
      queryInterface.removeColumn('Users', 'bio'),
    ]);
  },
};
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Step 3 - Update the model with the new fields

Step 4 - Run migration

npx sequelize-cli db:migrate

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That is it, you have successfully added new fields to an existing migration.

Top comments (13)

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germantellezv profile image
Germán Téllez Vanegas

Hi, great tutorial. Does this keep the data in the database? or does it remove all data?

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ebzeal profile image
Olusola Ajayi

"npx sequelize-cli db:migrate" keeps the data in the database. To wipe the database you'd need to do "npx sequelize-cli db:migrate:undo:all" before "npx sequelize-cli db:migrate"

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rdecker573 profile image
rdecker573

If a migration is rolled back, I think that will remove data.

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sammykapienga profile image
sammy kapienga

Keeps data

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saikat_banerjee_dd614d16b profile image
Saikat Banerjee

How to maintain sequence of the coloumn to be added while creating the coloumn. if I need to add the coloumn after a particular coloumn which already exists. By the above implementation the coloumn will always be added at the end of the list.

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nicola_lauritano_93149f83 profile image
Nicola Lauritano

Hi all,

When I run npx sequelize-cli db:migrate I got this error:

Cannot find "{myPath}/config/config.json". Have you run "sequelize init"?

I don't have a config.json file, should I create it or maybe it should be created by npx sequelize-cli migration:create --name modify_users_add_new_fields ?

If I have to create, how it should be?

Thanks all guys

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vladorjiggy profile image
vladorjiggy

This tutorial describes how to extend a existing migration. If you haven't used the CLI for your project, you have to initialize it by npx sequelize init

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mwibutsa profile image
Mwibutsa Floribert

Thanks, this was helpful

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guryashzone profile image
Guryash Singh

How can we add a column after specific column?

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dmikester1 profile image
Mike Dodge

Like this:
return Promise.all([
queryInterface.addColumn(
'users', // table name
'verifier', // new field name
{
type: Sequelize.STRING,
allowNull: true,
after: 'manager_bonus',
}
),
]);

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msamgan profile image
Mohammed Samgan Khan

what fi i want to add the new field after a particular field.

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let_mikev profile image
Miguel V

Luv ya Chinedu!

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mohamedhamada profile image
Mohamed Hamada

Thanks very much !
there is no much tutorials for these things out there!

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