database-migration

# Database Migration Master database schema and data migrations across ORMs (Sequelize, TypeORM, Prisma), including rollback strategies and zero-downtime deployments. ## When to Use This Skill - Migrating between different ORMs - Performing schema transformations - Moving data between databases - Implementing rollback procedures - Zero-downtime deployments - Database version upgrades - Data model refactoring ## ORM Migrations ### Sequelize Migrations ```javascript // migrations/20231201-create-users.js module.exports = { up: async (queryInterface, Sequelize) => { await queryInterface.createTable("users", { id: { type: Sequelize.INTEGER, primaryKey: true, autoIncrement: true, }, email: { type: Sequelize.STRING, unique: true, allowNull: false, }, createdAt: Sequelize.DATE, updatedAt: Sequelize.DATE, }); }, down: async (queryInterface, Sequelize) => { await queryInterface.dropTable("users"); }, }; // Run: npx sequelize-cli db:migrate // Rollback: npx sequelize-cli db:migrate:undo ``` ### TypeORM Migrations ```typescript // migrations/1701234567-CreateUsers.ts import { MigrationInterface, QueryRunner, Table } from "typeorm"; export class CreateUsers1701234567 implements MigrationInterface { public async up(queryRunner: QueryRunner): Promise<void> { await queryRunner.createTable( new Table({ name: "users", columns: [ { ...