Drizzle DBML Generator

Generate DBML markup from your schema defined with Drizzle ORM. Works with any dialect.

Generate DBML

To generate the DBML markup from your schema, all you have to do is run a script that executes the generate function of the dialect you're working with. To do that, you must install ts-node, and drizzle-dbml-generator of course.

# npm
npm i -D drizzle-dbml-generator ts-node
# yarn
yarn add -D drizzle-dbml-generator ts-node
# pnpm
pnpm add -D drizzle-dbml-generator ts-node

Example

schema.ts

import {
  boolean,
  integer,
  pgTable,
  primaryKey,
  serial,
  text,
  timestamp,
  varchar
} from 'drizzle-orm/pg-core';
import { relations } from 'drizzle-orm';

export const users = pgTable('users', {
  id: serial('id').primaryKey(),
  registeredAt: timestamp('registered_at').notNull().defaultNow(),
  username: varchar('username', { length: 16 }).notNull().unique('uq_users_username'),
  bio: text('bio'),
  hasBlue: boolean('has_blue').notNull().default(false)
});

export const usersRelations = relations(users, ({ many }) => ({
  followers: many(followers, { relationName: 'user_followers' }),
  following: many(followers, { relationName: 'user_follows' }),
  tweets: many(tweets),
  likes: many(likes)
}));

export const followers = pgTable(
  'followers',
  {
    userId: integer('user_id')
      .notNull()
      .references(() => users.id),
    followsUserId: integer('follows_user_id')
      .notNull()
      .references(() => users.id)
  },
  (followers) => ({
    pk: primaryKey(followers.userId, followers.followsUserId)
  })
);

export const followersRelations = relations(followers, ({ one }) => ({
  user: one(users, {
    fields: [followers.userId],
    references: [users.id],
    relationName: 'user_followers'
  }),
  followsUser: one(users, {
    fields: [followers.followsUserId],
    references: [users.id],
    relationName: 'user_follows'
  })
}));

export const tweets = pgTable('tweets', {
  id: serial('id').primaryKey(),
  postedAt: timestamp('posted_at').notNull().defaultNow(),
  content: text('content').notNull(),
  postedById: integer('posted_by_id')
    .notNull()
    .references(() => users.id)
});

export const tweetsRelations = relations(tweets, ({ one }) => ({
  postedBy: one(users, {
    fields: [tweets.postedById],
    references: [users.id]
  })
}));

export const likes = pgTable(
  'likes',
  {
    likedTweetId: integer('liked_tweet_id')
      .notNull()
      .references(() => tweets.id),
    likedById: integer('liked_by_id')
      .notNull()
      .references(() => users.id)
  },
  (likes) => ({
    pk: primaryKey(likes.likedById, likes.likedTweetId)
  })
);

export const likesRelations = relations(likes, ({ one }) => ({
  likedTweet: one(tweets, {
    fields: [likes.likedTweetId],
    references: [tweets.id]
  }),
  likedBy: one(users, {
    fields: [likes.likedById],
    references: [users.id]
  })
}));

dbml.ts

import * as schema from './schema';
import { pgGenerate } from 'drizzle-dbml-generator'; // Using Postgres for this example

const out = './schema.dbml';
const relational = true;

pgGenerate({ schema, out, relational });

Running the following command will generate the file with the DBML:

# You can add this as a package.json script
node --experimental-specifier-resolution=node --loader ts-node/esm dbml.ts

schema.dbml

table users {
  id serial [pk, not null, increment]
  registered_at timestamp [not null, default: `now()`]
  username varchar(16) [not null, unique]
  bio text
  has_blue boolean [not null, default: false]
}

table followers {
  user_id integer [not null]
  follows_user_id integer [not null]

  indexes {
    (user_id, follows_user_id) [pk]
  }
}

table tweets {
  id serial [pk, not null, increment]
  posted_at timestamp [not null, default: `now()`]
  content text [not null]
  posted_by_id integer [not null]
}

table likes {
  liked_tweet_id integer [not null]
  liked_by_id integer [not null]

  indexes {
    (liked_by_id, liked_tweet_id) [pk]
  }
}

ref followers_user_id_users_id_fk: followers.user_id > users.id [delete: no action, update: no action]

ref followers_follows_user_id_users_id_fk: followers.follows_user_id > users.id [delete: no action, update: no action]

ref tweets_posted_by_id_users_id_fk: tweets.posted_by_id > users.id [delete: no action, update: no action]

ref likes_liked_tweet_id_tweets_id_fk: likes.liked_tweet_id > tweets.id [delete: no action, update: no action]

ref likes_liked_by_id_users_id_fk: likes.liked_by_id > users.id [delete: no action, update: no action]

Options

pgGenerate

| Option | Type | Description | | ---------- | -------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | schema | PgSchema | An object containing Postgres dialect tables, enums and relations | | out? | string | The output directory and file name. Uses the current working directory as the root. If not set, it will not write the DBML file. | | relational | boolean? | If set to true, it will create references based on the relations generated with the relations function instead of foreign keys. Useful for databases that don't support foreign keys. Default: false. |

mysqlGenerate

| Option | Type | Description | | ---------- | ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | schema | MySqlSchema | An object containing MySQL dialect tables and relations | | out? | string | The output directory and file name. Uses the current working directory as the root. If not set, it will not write the DBML file. | | relational | boolean? | If set to true, it will create references based on the relations generated with the relations function instead of foreign keys. Useful for databases that don't support foreign keys. Default: false. |

sqliteGenerate

| Option | Type | Description | | ---------- | ------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | schema | SQLiteSchema | An object containing SQLite dialect tables and relations | | out? | string | The output directory and file name. Uses the current working directory as the root. If not set, it will not write the DBML file. | | relational | boolean? | If set to true, it will create references based on the relations generated with the relations function instead of foreign keys. Useful for databases that don't support foreign keys. Default: false. |

All generate functions return the DBML as a string regardless if a file is written or not, in case you want to do something with the generated DBML.