https://docs.nestjs.com/

TypeORM migration

Objectives

Generate and use migrations instead of syncing database. In dev and prod. This is the recommended method by TypeORM once you have data on prod, to avoid any loss.

Pre-requisites

TypeORM installed: https://docs.nestjs.com/techniques/database

Install

src/app.module.ts

import { DynamicModule, Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { TypeOrmModule } from '@nestjs/typeorm';
import * as ormconfig from './ormconfig';

export function DatabaseOrmModule(): DynamicModule {
  // we could load the configuration from dotEnv here,
  // but typeORM cli would not be able to find the configuration file.

  return TypeOrmModule.forRoot(ormconfig);
}

@Module({
  imports: [
    TypeOrmModule.forRoot(ormconfig)
    // or
    // DatabaseOrmModule(),
  ],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

src/ormconfig.ts

import {ConnectionOptions} from 'typeorm';

// You can load you .env file here synchronously using dotenv package (not installed here),
// import * as dotenv from 'dotenv';
// import * as fs from 'fs';
// const environment = process.env.NODE_ENV || 'development';
// const data: any = dotenv.parse(fs.readFileSync(`${environment}.env`));
// You can also make a singleton service that load and expose the .env file content.
// ...


// Check typeORM documentation for more information.
const config: ConnectionOptions = {
  type: 'postgres',
  host: 'localhost',
  port: 5432,
  username: 'postgres',
  password: 'pwd',
  database: 'migrationexample',
  entities: [__dirname + '/**/*.entity{.ts,.js}'],

  // We are using migrations, synchronize should be set to false.
  synchronize: false,

  // Run migrations automatically,
  // you can disable this if you prefer running migration manually.
  migrationsRun: true,
  logging: true,
  logger: 'file',

  // Allow both start:prod and start:dev to use migrations
  // __dirname is either dist or src folder, meaning either
  // the compiled js in prod or the ts in dev.
  migrations: [__dirname + '/migrations/**/*{.ts,.js}'],
  cli: {
    // Location of migration should be inside src folder
    // to be compiled into dist/ folder.
    migrationsDir: 'src/migrations',
  },
};

export = config;

package.json

"scripts": {
    "typeorm": "ts-node -r tsconfig-paths/register ./node_modules/typeorm/cli.js --config src/ormconfig.ts",
    "typeorm:migrate": "npm run typeorm migration:generate -- -n",
    "typeorm:run": "npm run typeorm migration:run"
}

Usage

1. npm run typeorm:migrate <myEntity-migration>
2. Check your migration queries in src/migrations
3. npm run start:dev or npm run start:prod or npm run typeorm:run

If everything went well, you have up to date entites and a migrations table listing applied migrations.

Additionnal information

• If you set migrationsRun to false in ormconfig.ts, you will have to use npm run typeorm:run to apply the migration, otherwise all migrations are applied automatically at application start.
• If you do not set --config parameter typeorm seek a valid configuration file at the root of the project.
• You do not want ormconfig.ts at the root of the project, otherwise it change /dist structure, you would have to change start:prod: node dist/main.js to start:prod: node dist/src/main.js.

@SeeAlso https://github.com/typeorm/typeorm/blob/master/docs/migrations.md
@SeeAlso https://github.com/typeorm/typeorm/blob/master/docs/using-cli.md#notes-on-entity-files-written-in-typescript