# Create Database Migration > 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. Use this skill whenever the task involves modifying Ghost's database schema — including adding, removing, or renaming columns or tables, adding new settings, creating indexes, updating data, or any change that requires a migration file in ghost/core. Also use when the user references schema.js, knex-migrator, the migrations directory, or asks to "add a field" or "add a column" to any Ghost model/table. Even if the user frames it as a feature or Linear issue, if the implementation requires a schema change, this skill applies. Use when this capability is needed. - Skill: `tomevault-io/create-database-migration` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/create-database-migration` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/create-database-migration/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/create-database-migration --- # Create Database Migration ## Instructions 1. Create a new, empty migration file: `cd ghost/core && pnpm migrate:create `. IMPORTANT: do not create the migration file manually; always use this script to create the initial empty migration file. The slug must be kebab-case (e.g. `add-column-to-posts`). 2. The above command will create a new directory in `ghost/core/core/server/data/migrations/versions` if needed, create the empty migration file with the appropriate name, and bump the core and admin package versions to RC if this is the first migration after a release. 3. 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/*`. 4. 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. 5. Test the migration manually: `cd ghost/core && pnpm knex-migrator migrate --v {version directory} --force` 6. If adding or dropping a table, update `ghost/core/core/server/data/exporter/table-lists.js` as appropriate. 7. If adding or dropping a table, also add or remove the table name from the expected tables list in `ghost/core/test/integration/exporter/exporter.test.js`. This test has a hardcoded alphabetically-sorted array of all database tables — it runs in CI integration tests (not unit tests) and will fail if the new table is missing. 8. Run the schema integrity test, and update the hash: `cd ghost/core && pnpm test:single test/unit/server/data/schema/integrity.test.js` 9. Run unit tests in Ghost core, and iterate until they pass: `cd ghost/core && pnpm test:unit` ## Examples See [examples.md](examples.md) for example migrations. ## Rules See [rules.md](rules.md) for rules that should always be followed when creating database migrations. --- > Source: [TryGhost/Ghost](https://github.com/TryGhost/Ghost) — distributed by [TomeVault](https://tomevault.io).