Database and Migrations

This chapter creates the blog schema: categories, tags, posts, and the post/tag pivot table.

What you will build

• category records for archives
• tag records for filtering
• post records with draft and published states
• a many-to-many table between posts and tags

Files you will create

server/db/migrations/create_categories.ts
server/db/migrations/create_tags.ts
server/db/migrations/create_posts.ts
server/db/migrations/create_post_tags.ts

The finished example uses these files:

• apps/blog-next/server/db/migrations/2026_04_26_000100_create_categories.ts
• apps/blog-next/server/db/migrations/2026_04_26_000110_create_tags.ts
• apps/blog-next/server/db/migrations/2026_04_26_000120_create_posts.ts
• apps/blog-next/server/db/migrations/2026_04_26_000130_create_post_tags.ts

Categories

import { defineMigration } from '@holo-js/db'

export default defineMigration({
  async up({ schema }) {
    await schema.createTable('categories', (table) => {
      table.id()
      table.string('name')
      table.string('slug').unique()
      table.text('description').nullable()
      table.timestamps()
    })
  },
  async down({ schema }) {
    await schema.dropTable('categories')
  },
})

Tags

import { defineMigration } from '@holo-js/db'

export default defineMigration({
  async up({ schema }) {
    await schema.createTable('tags', (table) => {
      table.id()
      table.string('name')
      table.string('slug').unique()
      table.timestamps()
    })
  },
  async down({ schema }) {
    await schema.dropTable('tags')
  },
})

Posts

import { defineMigration } from '@holo-js/db'

export default defineMigration({
  async up({ schema }) {
    await schema.createTable('posts', (table) => {
      table.id()
      table.integer('user_id')
      table.integer('category_id').nullable()
      table.string('title')
      table.string('slug').unique()
      table.string('status').default('draft')
      table.text('excerpt').nullable()
      table.text('body')
      table.timestamp('published_at').nullable()
      table.timestamps()
    })
  },
  async down({ schema }) {
    await schema.dropTable('posts')
  },
})

Post tags

import { defineMigration } from '@holo-js/db'

export default defineMigration({
  async up({ schema }) {
    await schema.createTable('post_tags', (table) => {
      table.integer('post_id')
      table.integer('tag_id')
      table.timestamps()
    })
  },
  async down({ schema }) {
    await schema.dropTable('post_tags')
  },
})

Run migrations

bun run migrate

Checkpoint

The database now has categories, tags, posts, and post_tags. The next chapter maps those tables to Holo models.

Related reference

• Database Migrations
• Database Commands
• Transactions