MikroOrm can't resolve drivers that i'm not currently using

[george-taschina]

Describe the bug
I am using MikroORM with NestJS and a dynamic configuration, but when I try to start the project, I encounter multiple "Module not found" errors for database drivers I am not using, such as:

Module not found: Error: Can't resolve 'pg'
Module not found: Error: Can't resolve 'oracledb'
Module not found: Error: Can't resolve 'better-sqlite3'
And others...

However, I am only using MySqlDriver.

Stack trace

ERROR in ../../node_modules/@mikro-orm/knex/dialects/mysql/MariaDbKnexDialect.js 10:15-42
Module not found: Error: Can't resolve 'mariadb/callback' in 'C:\Users\georg\Repos\George\has-george-read\node_modules\@mikro-orm\knex\dialects\mysql'
 @ ../../node_modules/@mikro-orm/knex/dialects/mysql/index.js 17:13-44
 @ ../../node_modules/@mikro-orm/knex/dialects/index.js 18:13-31
 @ ../../node_modules/@mikro-orm/knex/index.js 31:13-34
 @ ../../node_modules/@mikro-orm/mysql/index.js 19:13-39
 @ ./libs/book/src/repositories/book.repository.ts 6:16-43
 @ ./libs/book/src/book.module.ts 8:26-67
 @ ./apps/api/src/app.module.ts 5:22-69
 @ ./apps/api/src/main.ts 5:21-44

ERROR in ../../node_modules/@mikro-orm/knex/dialects/sqlite/BetterSqliteKnexDialect.js 8:15-40
Module not found: Error: Can't resolve 'better-sqlite3' in 'C:\Users\georg\Repos\George\has-george-read\node_modules\@mikro-orm\knex\dialects\sqlite'
 @ ../../node_modules/@mikro-orm/knex/dialects/sqlite/index.js 21:13-49
 @ ../../node_modules/@mikro-orm/knex/dialects/index.js 20:13-32
 @ ../../node_modules/@mikro-orm/knex/index.js 31:13-34
 @ ../../node_modules/@mikro-orm/mysql/index.js 19:13-39
 @ ./libs/book/src/repositories/book.repository.ts 6:16-43
 @ ./libs/book/src/book.module.ts 8:26-67
 @ ./apps/api/src/app.module.ts 5:22-69
 @ ./apps/api/src/main.ts 5:21-44

ERROR in ../../node_modules/@mikro-orm/knex/dialects/sqlite/LibSqlKnexDialect.js 11:15-32
Module not found: Error: Can't resolve 'libsql' in 'C:\Users\georg\Repos\George\has-george-read\node_modules\@mikro-orm\knex\dialects\sqlite'
 @ ../../node_modules/@mikro-orm/knex/dialects/sqlite/index.js 22:13-43
 @ ../../node_modules/@mikro-orm/knex/dialects/index.js 20:13-32
 @ ../../node_modules/@mikro-orm/knex/index.js 31:13-34
 @ ../../node_modules/@mikro-orm/mysql/index.js 19:13-39
 @ ./libs/book/src/repositories/book.repository.ts 6:16-43
 @ ./libs/book/src/book.module.ts 8:26-67
 @ ./apps/api/src/app.module.ts 5:22-69
 @ ./apps/api/src/main.ts 5:21-44

ERROR in ../../node_modules/knex/lib/dialects/better-sqlite3/index.js 7:11-36
Module not found: Error: Can't resolve 'better-sqlite3' in 'C:\Users\georg\Repos\George\has-george-read\node_modules\knex\lib\dialects\better-sqlite3'
 @ ../../node_modules/@mikro-orm/knex/MonkeyPatchable.js 34:41-84
 @ ../../node_modules/@mikro-orm/knex/index.js 26:13-41
 @ ../../node_modules/@mikro-orm/mysql/index.js 19:13-39
 @ ./libs/book/src/repositories/book.repository.ts 6:16-43
 @ ./libs/book/src/book.module.ts 8:26-67
 @ ./apps/api/src/app.module.ts 5:22-69
 @ ./apps/api/src/main.ts 5:21-44

ERROR in ../../node_modules/knex/lib/dialects/mssql/index.js 94:16-34
Module not found: Error: Can't resolve 'tedious' in 'C:\Users\georg\Repos\George\has-george-read\node_modules\knex\lib\dialects\mssql'
 @ ../../node_modules/@mikro-orm/knex/MonkeyPatchable.js 24:32-66
 @ ../../node_modules/@mikro-orm/knex/index.js 26:13-41
 @ ../../node_modules/@mikro-orm/mysql/index.js 19:13-39
 @ ./libs/book/src/repositories/book.repository.ts 6:16-43
 @ ./libs/book/src/book.module.ts 8:26-67
 @ ./apps/api/src/app.module.ts 5:22-69
 @ ./apps/api/src/main.ts 5:21-44

ERROR in ../../node_modules/knex/lib/dialects/mysql/index.js 24:11-27
Module not found: Error: Can't resolve 'mysql' in 'C:\Users\georg\Repos\George\has-george-read\node_modules\knex\lib\dialects\mysql'
 @ ../../node_modules/knex/lib/dialects/mysql2/index.js 3:21-40
 @ ../../node_modules/@mikro-orm/knex/MonkeyPatchable.js 12:33-68
 @ ../../node_modules/@mikro-orm/knex/index.js 26:13-41
 @ ../../node_modules/@mikro-orm/mysql/index.js 19:13-39
 @ ./libs/book/src/repositories/book.repository.ts 6:16-43
 @ ./libs/book/src/book.module.ts 8:26-67
 @ ./apps/api/src/app.module.ts 5:22-69
 @ ./apps/api/src/main.ts 5:21-44

ERROR in ../../node_modules/knex/lib/dialects/oracledb/index.js 44:21-40
Module not found: Error: Can't resolve 'oracledb' in 'C:\Users\georg\Repos\George\has-george-read\node_modules\knex\lib\dialects\oracledb'
 @ ../../node_modules/knex/lib/dialects/index.js 12:18-39
 @ ../../node_modules/knex/lib/knex-builder/internal/config-resolver.js 5:36-61
 @ ../../node_modules/knex/lib/knex-builder/Knex.js 7:26-63
 @ ../../node_modules/knex/lib/index.js 1:13-43
 @ ../../node_modules/knex/knex.js 8:13-35
 @ ../../node_modules/@mikro-orm/knex/index.js 38:13-28
 @ ../../node_modules/@mikro-orm/mysql/index.js 19:13-39
 @ ./libs/book/src/repositories/book.repository.ts 6:16-43
 @ ./libs/book/src/book.module.ts 8:26-67
 @ ./apps/api/src/app.module.ts 5:22-69
 @ ./apps/api/src/main.ts 5:21-44

ERROR in ../../node_modules/knex/lib/dialects/oracledb/utils.js 40:19-38
Module not found: Error: Can't resolve 'oracledb' in 'C:\Users\georg\Repos\George\has-george-read\node_modules\knex\lib\dialects\oracledb'
 @ ../../node_modules/knex/lib/dialects/oracledb/index.js 16:4-22
 @ ../../node_modules/knex/lib/dialects/index.js 12:18-39
 @ ../../node_modules/knex/lib/knex-builder/internal/config-resolver.js 5:36-61
 @ ../../node_modules/knex/lib/knex-builder/Knex.js 7:26-63
 @ ../../node_modules/knex/lib/index.js 1:13-43
 @ ../../node_modules/knex/knex.js 8:13-35
 @ ../../node_modules/@mikro-orm/knex/index.js 38:13-28
 @ ../../node_modules/@mikro-orm/mysql/index.js 19:13-39
 @ ./libs/book/src/repositories/book.repository.ts 6:16-43
 @ ./libs/book/src/book.module.ts 8:26-67
 @ ./apps/api/src/app.module.ts 5:22-69
 @ ./apps/api/src/main.ts 5:21-44

ERROR in ../../node_modules/knex/lib/dialects/pgnative/index.js 13:11-31
Module not found: Error: Can't resolve 'pg' in 'C:\Users\georg\Repos\George\has-george-read\node_modules\knex\lib\dialects\pgnative'
 @ ../../node_modules/knex/lib/dialects/index.js 13:18-39
 @ ../../node_modules/knex/lib/knex-builder/internal/config-resolver.js 5:36-61
 @ ../../node_modules/knex/lib/knex-builder/Knex.js 7:26-63
 @ ../../node_modules/knex/lib/index.js 1:13-43
 @ ../../node_modules/knex/knex.js 8:13-35
 @ ../../node_modules/@mikro-orm/knex/index.js 38:13-28
 @ ../../node_modules/@mikro-orm/mysql/index.js 19:13-39
 @ ./libs/book/src/repositories/book.repository.ts 6:16-43
 @ ./libs/book/src/book.module.ts 8:26-67
 @ ./apps/api/src/app.module.ts 5:22-69
 @ ./apps/api/src/main.ts 5:21-44

ERROR in ../../node_modules/knex/lib/dialects/postgres/index.js 63:11-24
Module not found: Error: Can't resolve 'pg' in 'C:\Users\georg\Repos\George\has-george-read\node_modules\knex\lib\dialects\postgres'
 @ ../../node_modules/@mikro-orm/knex/MonkeyPatchable.js 26:35-72
 @ ../../node_modules/@mikro-orm/knex/index.js 26:13-41
 @ ../../node_modules/@mikro-orm/mysql/index.js 19:13-39
 @ ./libs/book/src/repositories/book.repository.ts 6:16-43
 @ ./libs/book/src/book.module.ts 8:26-67
 @ ./apps/api/src/app.module.ts 5:22-69
 @ ./apps/api/src/main.ts 5:21-44

ERROR in ../../node_modules/knex/lib/dialects/postgres/index.js 192:8-34
Module not found: Error: Can't resolve 'pg-query-stream' in 'C:\Users\georg\Repos\George\has-george-read\node_modules\knex\lib\dialects\postgres'
 @ ../../node_modules/@mikro-orm/knex/MonkeyPatchable.js 26:35-72
 @ ../../node_modules/@mikro-orm/knex/index.js 26:13-41
 @ ../../node_modules/@mikro-orm/mysql/index.js 19:13-39
 @ ./libs/book/src/repositories/book.repository.ts 6:16-43
 @ ./libs/book/src/book.module.ts 8:26-67
 @ ./apps/api/src/app.module.ts 5:22-69
 @ ./apps/api/src/main.ts 5:21-44

ERROR in ../../node_modules/knex/lib/dialects/redshift/index.js 44:11-24
Module not found: Error: Can't resolve 'pg' in 'C:\Users\georg\Repos\George\has-george-read\node_modules\knex\lib\dialects\redshift'
 @ ../../node_modules/knex/lib/dialects/index.js 15:18-39
 @ ../../node_modules/knex/lib/knex-builder/internal/config-resolver.js 5:36-61
 @ ../../node_modules/knex/lib/knex-builder/Knex.js 7:26-63
 @ ../../node_modules/knex/lib/index.js 1:13-43
 @ ../../node_modules/knex/knex.js 8:13-35
 @ ../../node_modules/@mikro-orm/knex/index.js 38:13-28
 @ ../../node_modules/@mikro-orm/mysql/index.js 19:13-39
 @ ./libs/book/src/repositories/book.repository.ts 6:16-43
 @ ./libs/book/src/book.module.ts 8:26-67
 @ ./apps/api/src/app.module.ts 5:22-69
 @ ./apps/api/src/main.ts 5:21-44

ERROR in ../../node_modules/knex/lib/dialects/sqlite3/index.js 42:11-29
Module not found: Error: Can't resolve 'sqlite3' in 'C:\Users\georg\Repos\George\has-george-read\node_modules\knex\lib\dialects\sqlite3'
 @ ../../node_modules/@mikro-orm/knex/MonkeyPatchable.js 32:34-70
 @ ../../node_modules/@mikro-orm/knex/index.js 26:13-41
 @ ../../node_modules/@mikro-orm/mysql/index.js 19:13-39
 @ ./libs/book/src/repositories/book.repository.ts 6:16-43
 @ ./libs/book/src/book.module.ts 8:26-67
 @ ./apps/api/src/app.module.ts 5:22-69
 @ ./apps/api/src/main.ts 5:21-44

To Reproduce
Steps to reproduce the behavior:

1. Create a database.config.loader.ts file

import { DatabaseConfig, databaseConfigCodec } from '../types/database-config';
import * as E from 'fp-ts/Either';
import { registerAs } from '@nestjs/config';

const databaseConfig = (): DatabaseConfig | never =>
  pipe(
    {
      type: process.env.MIKRO_ORM_CONNECTION,
      host: process.env.MIKRO_ORM_HOST,
      port: process.env.MIKRO_ORM_PORT,
      username: process.env.MIKRO_ORM_USER,
      password: process.env.MIKRO_ORM_PASSWORD,
      name: process.env.MIKRO_ORM_DB_NAME,
      debug: process.env.MIKRO_ORM_DEBUG || 'disabled',
    },
    databaseConfigCodec.decode,
    E.mapLeft((errors) => {
      throw new Error(
        `Errore durante la decodifica del database: ${errors.map((error) => error.message).join('\n')}`
      );
    }),
    E.getOrElseW((config) => config)
  );

export const databaseConfigLoader = registerAs(
  'databaseConfig',
  databaseConfig
);

export const DATABASE_CONFIG_KEY = databaseConfigLoader.KEY;

2. Define the database config in database-config.ts:

import * as t from 'io-ts';
import * as types from 'io-ts-types';

export const databaseConfigCodec = t.type(
  {
    type: t.literal('mysql'),
    host: t.string,
    port: types.IntFromString,
    username: t.string,
    password: t.string,
    name: t.string,
    debug: t.string,
  },
  'databaseConfig'
);

export type DatabaseConfig = t.TypeOf<typeof databaseConfigCodec>;

3. Set up the database module factory and load it in the root module:

import { DatabaseConfig } from '../types/database-config';
import { MikroOrmModule } from '@mikro-orm/nestjs';
import { ConfigModule } from '@nestjs/config';
import { databaseConfigLoader } from '../config/database-config.loader';
import { MySqlDriver } from '@mikro-orm/mysql';

export const databaseModuleFactory = () =>
  MikroOrmModule.forRootAsync({
    imports: [ConfigModule.forFeature(databaseConfigLoader)],
    useFactory: (config: DatabaseConfig) => ({
      dbName: config.name,
      user: config.username,
      password: config.password,
      host: config.host,
      port: config.port,
      driver: MySqlDriver,
      entities: ['../../../../dist/**/*.entity.js'],
      entitiesTs: ['../../../../libs/**/*.entity.ts'],
      debug: config.debug === 'true',
      autoLoadEntities: true,
    }),
  });

Expected behavior

• MikroORM should start without attempting to resolve database drivers that are not in use.

Additional context

• The project is running in a monorepo workspace.

Versions

Dependency	Version
node	v20.15.0
typescript	5.1.3
mikro-orm	6.4.5
@nestjs/core	^11.0.0

[B4nan]

This is caused by using a bundler, it's up to you to configure it properly and mark those dependencies as external. We mark all those as optional peer dependencies, I don't see what else I could do. I believe this is specifically a webpack problem, modern bundlers like vite should resolve this correctly and respect the optional peer dependencies.

Note that some of those errors are coming from knex, not the ORM itself.

[george-taschina]

Thank you so much! I took a deeper look into this documentation and found a list of dependencies that needed to be excluded from the build.