create-migration

Create Migration

Create a new database migration file with proper structure.

Your Task

Generate a migration file for database schema changes.

Arguments

• $1: Migration name (required) - descriptive name like "create_users_table" or "add_email_to_users"

Steps

1. Determine migration tool:

   • Check for Knex (knexfile.js)
   • Check for TypeORM (ormconfig.json)
   • Check for Prisma (schema.prisma)
   • Check for Sequelize (.sequelizerc)
   • Default to Knex if none found

2. Generate timestamp:

   const timestamp = Date.now();
   const filename = `${timestamp}_${migrationName}.js`;
   

3. Create migration file:

   For Knex:

   // migrations/20240101120000_create_users_table.js
   
   exports.up = async function(knex) {
     await knex.schema.createTable('users', (table) => {
       table.increments('id').primary();
       table.string('email').unique().notNullable();
       table.string('password_hash').notNullable();
       table.timestamps(true, true);
     });
   };
   
   exports.down = async function(knex) {
     await knex.schema.dropTable('users');
   };
   

   For adding columns:

   exports.up = async function(knex) {
     await knex.schema.table('users', (table) => {
       table.string('phone', 20);
       table.boolean('is_verified').defaultTo(false);
     });
   };
   
   exports.down = async function(knex) {
     await knex.schema.table('users', (table) => {
       table.dropColumn('phone');
       table.dropColumn('is_verified');
     });
   };
   

   For adding indexes:

   exports.up = async function(knex) {
     await knex.schema.table('posts', (table) => {
       table.index('user_id');
       table.index(['user_id', 'created_at']);
     });
   };
   
   exports.down = async function(knex) {
     await knex.schema.table('posts', (table) => {
       table.dropIndex('user_id');
       table.dropIndex(['user_id', 'created_at']);
     });
   };