Entity Generator

To generate entities from existing database schema, you can use EntityGenerator helper.

You can use it via CLI:

To work with the CLI, first install @mikro-orm/cli package locally. The version needs to be aligned with the @mikro-orm/core package.

npx mikro-orm generate-entities --dump  # Dumps all generated entities
npx mikro-orm generate-entities --save --path=./my-entities  # Saves entities into given directory

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

./generate-entities.ts

import { MikroORM } from '@mikro-orm/core';

(async () => {
  const orm = await MikroORM.init({
    discovery: {
      // we need to disable validation for no entities
      warnWhenNoEntities: false,
    },
    dbName: 'your-db-name',
    // ...
  });
  const generator = orm.getEntityGenerator();
  const dump = await generator.generate({
    save: true,
    baseDir: process.cwd() + '/my-entities',
  });
  console.log(dump);
  await orm.close(true);
})();

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

$ ts-node generate-entities

Advanced configuration

By default, the EntityGenerator generates only owning sides of relations (e.g. M:1) and uses decorators for the entity definition. We can adjust its behaviour via entityGenerator section in the ORM config. Available options:

• bidirectionalRelations to generate also the inverse sides for them
• identifiedReferences to generate M:1 and 1:1 relations as wrapped references
• entitySchema to generate the entities using EntitySchema instead of decorators
• esmImport to use esm style import for imported entities e.x. when esmImport=true, generated entities include import Author from './Author.js'
• skipTables to ignore some database tables (accepts array of table names)
• skipColumns to ignore some database tables columns (accepts an object, keys are table names with schema prefix if available, values are arrays of column names)

const dump = await orm.entityGenerator.generate({
  save: true,
  baseDir: process.cwd() + '/my-entities',
  skipTables: ['book', 'author'],
  skipColumns: {
    'public.user': ['email', 'middle_name'],
  },
});

Current limitations

• in mysql, tinyint columns will be defined as boolean properties