[Angular][Nest.js] Add TypeOrm

Intro

This time I added TypeOrm into the Nest.js project.
[Angular 10 + NgRx + Nest.js] Create project

Use TypeOrm

Install

To use TypeOrm I installed some packages. 

[PostgreSQL] Play with TypeORM 1 

And to integrate the Nest.js project, I add an additional package.

npm install --save @nestjs/typeorm typeorm pg

Database | NestJS - A progressive Node.js framework

Configuration

Last time I used "ormconfig.json" for TypeOrm configuration. In Nest.js projects, I also could write them in "app.module.ts".

server/app.module.ts

import { Module } from '@nestjs/common';
import { AngularUniversalModule } from '@nestjs/ng-universal';
import { TypeOrmModule } from '@nestjs/typeorm';
import { join } from 'path';
import { Workflow } from './entities/workflow.entity';

@Module({
  imports: [
    AngularUniversalModule.forRoot({
      viewsPath: join(process.cwd(), 'dist/browser'),
      bundle: require('../server/main'),
      liveReload: false
    }),
    TypeOrmModule.forRoot({
      type: "postgres",
      host: "localhost",
      port: 5432,
      username: "test",
      password: "test",
      database: "Example",
      entities: [Workflow],
      synchronize: true,
      logging: true,
      cache: false
    })
  ],
  controllers: [],
  providers: []
})
export class ApplicationModule {}

My choice

But I choosed using "ormconfig.json". When I migrated Database by migration files, I had to use TypeOrm commands. But TypeOrm commands couldn't read "app.module.ts". So I must add the "ormconfig.json" file anyway.

ormconfig.json

{
    "type": "postgres",
    "host": "localhost",
    "port": 5432,
    "username": "test",
    "password": "test",
    "database": "Example",
    "entities": ["dist/**/entities/*.entity{.ts,.js}"],
    "migrations": ["server/migrations/*.{.ts,.js}"],
    "synchronize": true,
    "logging": true,
    "cache": false,
    "cli": {
        "entitiesDir": "server/entities",
        "migrationsDir": "server/migrations"
    }
}

So I removed the configure informations from "app.module.ts".

server/app.module.ts

...
@Module({
  imports: [
...
    TypeOrmModule.forRoot()
  ],
  controllers: [],
  providers: []
})
export class ApplicationModule {}

Add an Entity class

server/entities/workflow.entity.ts

import {Entity, PrimaryGeneratedColumn, Column, OneToMany, UpdateDateColumn} from "typeorm";

@Entity("Workflow")
export class Workflow {
    @PrimaryGeneratedColumn()
    id: number = -1;
    @Column({ type: 'text', nullable: false })
    createUserMail: string = '';
    @Column({ type: 'timestamp with time zone', nullable: true })
    circulationLimit: Date|null = null;
    @Column({ type: 'timestamp with time zone', nullable: false })
    lastUpdateDate: Date = new Date();
    
    public create(createUserMail: string, circulationLimit: Date|null) {
        if (createUserMail == null ||
            createUserMail.length <= 0) {
            throw new Error("Can not set createUserMail empty");
        }
        this.createUserMail = createUserMail;
        this.update(circulationLimit);
    }
    public update(circulationLimit: Date|null) {
        this.circulationLimit = circulationLimit;
        this.lastUpdateDate = new Date();
    }
}

Use "nest generate"

To access TypeOrm classes, I wanted to add classes into the Nest.js project. But when I did "nest generate" command, the created files were put into "src" directory. How to change to "server"? I had to add nest-cli.json like below.

nest-cli.json

{
    "collection": "@nestjs/schematics",
    "sourceRoot": "server"
}

After I did this, the files could be into "server" directory.

Add "@nestjs/testing"

After I generated some classes(ex. controller, service, etc.), I got an error. It was because the test classes needed "@nestjs/testing" package.

npm install --save-dev @nestjs/testing

Access the Database by Repositories

Access the Database(failed)

I added one controller class and one service class to access the Database.

server/workflow/workflow.controller.ts

import { Controller, Get } from '@nestjs/common';
import { WorkflowService } from './workflow.service';
import { Workflow } from '../entities/workflow.entity';

@Controller('workflow')
export class WorkflowController {
    constructor(private readonly service: WorkflowService) {
    }
    @Get("search")
    public async getWorkflowItems(): Promise<Workflow[]> {
        return await this.service.findAll();
    }
}

server/workflow/workflow.service.ts

import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Workflow } from '../entities/workflow.entity';
import { Repository } from 'typeorm';
import { of } from 'rxjs';

@Injectable()
export class WorkflowService {
    constructor(
        @InjectRepository(Workflow)
        private workflowRepositiory: Repository<Workflow>
    ){}
    public findAll(): Promise<Workflow[]> {
        return this.workflowRepositiory.find();
    }
}

server/app.module.ts

...
import { WorkflowController } from './workflow/workflow.controller';
import { WorkflowService } from './workflow/workflow.service';
import { Workflow } from './entities/workflow.entity';

@Module({
  imports: [
...
  ],
  controllers: [WorkflowController],
  providers: [WorkflowService]
})
export class ApplicationModule {}

OK. I started serving the project. 

...And I got an error.

...
[Nest] 17376   - 07/11/2020, 8:22:27 PM   [ExceptionHandler] Nest can't resolve dependencies of the WorkflowService (?). Please make sure that the argument WorkflowRepository at index [0] is available in the ApplicationModule context.

Potential solutions:
- If WorkflowRepository is a provider, is it part of the current ApplicationModule?
- If WorkflowRepository is exported from a separate @Module, is that module imported within ApplicationModule?
  @Module({
    imports: [ /* the Module containing WorkflowRepository */ ]
  })
 +570ms
Error: Nest can't resolve dependencies of the WorkflowService (?). Please make sure that the argument WorkflowRepository at index [0] is available in the ApplicationModule context.

Potential solutions:
- If WorkflowRepository is a provider, is it part of the current ApplicationModule?
- If WorkflowRepository is exported from a separate @Module, is that module imported within ApplicationModule?
  @Module({
    imports: [ /* the Module containing WorkflowRepository */ ]
  })

    at Injector.lookupComponentInParentModules (C:\Users\example\Documents\workspace\proofreading-workflow\node_modules\@nestjs\core\injector\injector.js:190:19)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
[nodemon] app crashed - waiting for file changes before starting...

Resolve the dependencies

To resolve the dependencies of Repository class, I had to add a module.

server/app.module.ts

...
import { Workflow } from './entities/workflow.entity';

@Module({
  imports: [
...
    TypeOrmModule.forRoot(),
    TypeOrmModule.forFeature([Workflow])
  ],
  controllers: [ProofreaderController, WorkflowController],
  providers: [ProofreaderService, WorkflowService]
})
export class ApplicationModule {}

Finally, I could access the Database :).

Resources

• Database | NestJS - A progressive Node.js framework
• SQL (TypeORM) | NestJS - A progressive Node.js framework