Schema Generator

To generate schema from your entity metadata, you can use SchemaGenerator helper.

You can use it via CLI:

npx mikro-orm schema:create --dump   # Dumps create schema SQL
npx mikro-orm schema:update --dump   # Dumps update schema SQL
npx mikro-orm schema:drop --dump     # Dumps drop schema SQL

You can also use --run flag to fire all queries, but be careful as it might break your database. Be sure to always check the generated SQL first before executing. Do not use --run flag in production!

schema:create will automatically create the database if it does not exist.

schema:drop will by default drop all database tables. You can use --drop-db flag to drop the whole database instead.

Or you can create simple script where you initialize MikroORM like this:

./create-schema.ts

import { MikroORM } from 'mikro-orm';
(async () => {
  const orm = await MikroORM.init({
    entities: [Author, Book, ...],
    dbName: 'your-db-name',
    // ...
  });
  const generator = orm.getSchemaGenerator();
  const dropDump = await generator.getDropSchemaSQL();
  console.log(dropDump);
  const createDump = await generator.getCreateSchemaSQL();
  console.log(createDump);
  const updateDump = await generator.getUpdateSchemaSQL();
  console.log(updateDump);
  // there is also `generate()` method that returns drop + create queries
  const dropAndCreateDump = await generator.generate();
  console.log(dropAndCreateDump);
  // or you can run those queries directly, but be sure to check them first!
  await generator.dropSchema();
  await generator.createSchema();
  await generator.updateSchema();
  await orm.close(true);
})();

Then run this script via ts-node (or compile it to plain JS and use node):

$ ts-node create-schema