name	Create database migration
description	Create a database migration to add a table, add columns to an existing table, add a setting, or otherwise change the schema of Ghost's MySQL database.

Create Database Migration

Instructions

Change directories into ghost/core: cd ghost/core
Create a new, empty migration file using slimer: slimer migration <name-of-database-migration>. IMPORTANT: do not create the migration file manually; always use slimer to create the initial empty migration file.
The above command will create a new directory in ghost/core/core/server/data/migrations/versions if needed, and create the empty migration file with the appropriate name.
Update the migration file with the changes you want to make in the database, following the existing patterns in the codebase. Where appropriate, prefer to use the utility functions in ghost/core/core/server/data/migrations/utils/*.
Update the schema definition file in ghost/core/core/server/data/schema/schema.js, and make sure it aligns with the latest changes from the migration.
Test the migration manually: yarn knex-migrator migrate --v {version directory} --force
If adding or dropping a table, update ghost/core/core/server/data/exporter/table-lists.js as appropriate.
Run the schema integrity test, and update the hash: yarn test:single test/unit/server/data/schema/integrity.test.js
Run unit tests in Ghost core, and iterate until they pass: cd ghost/core && yarn test:unit

See examples.md for example migrations.

See rules.md for rules that should always be followed when creating database migrations.