Using multiple databases hustle

[demetris-manikas]

Hi!

I tried accessing two databases in my nestjs project using micro-orm (great by the way).

I spent a lot of time trying to figure out why using the documentation proposed way did not work for me.

When specifying a contextName for both database modules I was always getting weird errors about not having registered entities.

In the end after reading a post on how the same thing was implemented by nestjs/typeorm I tried to NOT set the contextName in one of the database modules and everything went smoothly after that.

If I am not missing something here I would suggest that this should be made clear in the docs that one of the database modules should be the default one (without a contextName defined) so that others are not affected as I was.

Thanks.

[B4nan]

It's hard to improve something when you don't say what is actually wrong. You are not supposed to use one instance without the context name in such setup. This sounds like you did not use the decorators property (since you need to put the context name in each ORM related decorator in that setup).

The docs in the readme here should be correct, if you think otherwise, please provide a failing repro.

[demetris-manikas]

I will if I get the time to.
Thanks for your prompt answer.

[demetris-manikas]

Hi.
I created here a stripped down version of what I was trying to do.
After cloning run docker compose up and it will fail,
Then remove the 'postgres' contextName from the database module and from the relevant controller and module and it will rise.

Thanks for your time.

[demetris-manikas]

Hi. Did you get to look into this?
Should I refile an issue?

[B4nan]

Sorry, I was out for the weekend and was swamped on Friday and today with work stuff. Only checked the code briefly and didn't see anything wrong, let me give it a closer look.

[B4nan]

The problem here is the use of useFactory with a parameter, the ORM adapter does not know how to resolve it, see #184.

Also you are missing registerRequestContext: false in the other forRoot call here, as well as the forMiddleware call.

[demetris-manikas]

Thanks a lot for taking the time to look into this.

Still my initial request holds.
These things must be documented.

More people will eventually call useFactory() with a parameter.

And reading this

You can define multiple database connections by registering multiple MikroOrmModule and setting their contextName. 

If you want to use middleware request context you must disable automatic middleware and register MikroOrmModule with forMiddleware() or use NestJS Injection Scope

I understood that setting registerRequestContext=false and forMiddleware should be used

if I want to use mikro-orm in middleware .

I will stick with only naming just one of the two since it is more convenient and it seems to work without the workarounds discused in #184 and without extra parameters definitions

MikroOrmModule.forRootAsync({
      imports: [ConfigModule],
      inject: [ConfigService],
      useFactory: (configService: ConfigService) => {
        return {
          autoLoadEntities: true,
          driver: PostgreSqlDriver,
          host: configService.get('EMPOWER_POSTGRES_HOST'),
          port: +configService.get<number>('EMPOWER_POSTGRES_PORT', 5432),
          user: configService.get('EMPOWER_POSTGRES_USER'),
          password: configService.get('EMPOWER_POSTGRES_PASSWORD'),
          dbName: configService.get('EMPOWER_POSTGRES_DB'),
          extensions: [Migrator],
        };
      },
    }),

    MikroOrmModule.forRootAsync({
      imports: [ConfigModule],
      inject: [ConfigService],
      contextName: 'empower-eclass',
      useFactory: (configService: ConfigService) => {
        return {
          autoLoadEntities: true,
          driver: MariaDbDriver,
          host: configService.get('EMPOWER_MARIADB_HOST'),
          port: +configService.get<number>('EMPOWER_MARIADB_PORT', 5432),
          user: configService.get('EMPOWER_MARIADB_USER'),
          password: configService.get('EMPOWER_MARIADB_PASSWORD'),
          dbName: configService.get('EMPOWER_MARIADB_DB'),
        };
      },
    }),
  ],

[demetris-manikas]

Consider this solved.

[B4nan]

The point is you are ignoring it explicitly.

[demetris-manikas]

Let me check.

[demetris-manikas]

I double checked it.
The problem lies on that I have to add the registerRequestContext: false property to both my setups. And I got confused by the docs because I understood that I have to set it only if I want to use the databases in middleware.
The ConfigService ignores the .env but the environment variables are set in the docker-compose file.

[demetris-manikas]

I updated the https://github.com/demetris-manikas/micro-orm-test repo.
Now it starts fine. If you remove the registerRequestContext: false property then it fails to start.
If you go on to remove the contextName from one of the two from the database module and the respective modules and services as well then it again loads fine