What are Node.js migrations and why are they important?

What are Node.js migrations and why are they important?

Node.js migrations are scripts that help manage changes to your database schema over time. They are important because they ensure that your database structure is consistent across different environments and help in tracking changes.

How do I create a migration in Node.js?

You can create a migration in Node.js using libraries like Knex.js or Sequelize. Typically, you would define a migration file that specifies the changes to be made, such as creating or altering tables.

Can you show me an example of a migration script?

Sure! Here's a simple example using Knex.js:

exports.up = function(knex) {
  return knex.schema.createTable('users', function(table) {
    table.increments();
    table.string('name');
    table.string('email').unique();
  });
};

exports.down = function(knex) {
  return knex.schema.dropTable('users');
};

What happens if I run a migration that fails?

If a migration fails, it typically rolls back the changes made during that migration, ensuring your database remains in a consistent state. However, it's essential to handle errors properly in your migration scripts.