schema-generator.md

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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!

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

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