Can't map primary key that is a foreign key to a composite key.

[erik-induro]

Describe the bug
I am using postgresql partitioned tables so most of my primary keys are composite keys. When I create a table with a foreign key to a composite primary key it fails to map.

Stack trace

TypeError: Cannot read property 'id' of undefined
    at /Users/me/projects/sandbox/mikro-orm-fk/node_modules/@mikro-orm/core/utils/Utils.js:369:29
    at Array.map (<anonymous>)
    at Function.getOrderedPrimaryKeys (/Users/me/projects/sandbox/mikro-orm-fk/node_modules/@mikro-orm/core/utils/Utils.js:367:33)
    at /Users/me/projects/sandbox/mikro-orm-fk/node_modules/@mikro-orm/core/utils/Utils.js:371:37
    at Array.map (<anonymous>)
    at Function.getOrderedPrimaryKeys (/Users/me/projects/sandbox/mikro-orm-fk/node_modules/@mikro-orm/core/utils/Utils.js:367:33)
    at /Users/me/projects/sandbox/mikro-orm-fk/node_modules/@mikro-orm/core/utils/Utils.js:371:37
    at Array.map (<anonymous>)
    at Function.getOrderedPrimaryKeys (/Users/me/projects/sandbox/mikro-orm-fk/node_modules/@mikro-orm/core/utils/Utils.js:367:33)
    at EntityFactory.findEntity (/Users/me/projects/sandbox/mikro-orm-fk/node_modules/@mikro-orm/core/entity/EntityFactory.js:95:35)
    at EntityFactory.create (/Users/me/projects/sandbox/mikro-orm-fk/node_modules/@mikro-orm/core/entity/EntityFactory.js:29:29)
    at SqlEntityManager.merge (/Users/me/projects/sandbox/mikro-orm-fk/node_modules/@mikro-orm/core/EntityManager.js:364:80)
    at SqlEntityManager.map (/Users/me/projects/sandbox/mikro-orm-fk/node_modules/@mikro-orm/core/EntityManager.js:346:21)
    at test (/Users/me/projects/sandbox/mikro-orm-fk/src/index.ts:39:9)
    at run (/Users/me/projects/sandbox/mikro-orm-fk/src/index.ts:61:2)
    at processTicksAndRejections (internal/process/task_queues.js:93:5)

To Reproduce

I created a minimal reproducible example here: https://github.com/erik-induro/mikro-orm-fk

Here are some examples that fail:

// just using the mapper
orm.em.map(UserRole, {
  user_id: 'cc455d1f-f4c7-4b57-b833-e6ca88239b61',
  user_organization_id: 'e3dca7ae-6389-49dc-931d-419716828a79',
  role: Role.admin,
});
// or query and map just the table
await this.em.find(UserRole, { user: { $eq: [userId, orgId] } })
// or try to populate it
await this.em.findOne(
  User,
  { id: { $eq: userId }, organization: { $eq: orgId } },
  { populate: { userRoles: LoadStrategy.JOINED } },
);

Expected behavior

I expect the data to map.

Additional context

If the FK is not the PK then it works fine.

Versions

Dependency	Version
node	14.15.3
typescript	4.2.3
mikro-orm	4.5.1
mikro-orm/postgresql	4.5.1

[Langstra]

From what I see in your code you are missing the following property.

[PrimaryKeyType]: [number, string];

https://mikro-orm.io/docs/composite-keys/#use-case-1-dynamic-attributes

[erik-induro]

@Langstra I'll add it back in but it doesn't fix the issue.

[B4nan]

The code is ok, PrimaryKeyType is just for TS, this is runtime issue.

Already got it reproduced, there are basically two problems, one with the em.map, the other with joined loading strategy (both resulting in same error, but with different code paths and causes).

[B4nan]

Lol, ok, just cracked the other issue with joined loading :D

[erik-induro]

@B4nan thanks for fixing this so quickly!

[B4nan]

Things like this have indeed priority! :]

You can try the fix via dev version btw (4.5.2-dev.3)

[erik-induro]

Thanks I was trying to figure out how to pull it in because I was dead in the water. Looks like it works for me!