What are ORMs and how do migrations work in Node.js?

What are ORMs and how do migrations work in Node.js?

ORMs, or Object-Relational Mappers, allow you to interact with databases using JavaScript objects. Migrations are scripts that help manage database schema changes.

Can you give me an example of how to create a migration in Node.js?

Sure! If you're using Sequelize, you can create a migration with the command npx sequelize-cli migration:generate --name create-users. This will create a new migration file.

What should I include in the migration file?

In the migration file, you typically define the up method to specify how to apply the changes, and the down method to revert them. For example, to create a users table, you might use queryInterface.createTable('users', { id: { type: Sequelize.INTEGER, primaryKey: true, autoIncrement: true }, name: Sequelize.STRING });.

How do I run the migration after creating it?

You can run the migration using the command npx sequelize-cli db:migrate. This will apply all pending migrations to your database.