nested joins: regression since v4.6.0?

There seems that a regression was introduced since v4.6.0

Here is my controller:

@Crud(
[...]
query: {
        join: {
            posts: {}
            posts.comments: {}
            posts.comments.user: {}
       }
})
export class PostsController {

And HTTP GET:

http://localhost:3000/posts?join=posts&join=posts.comments&join=posts.comments.user

Error:

Error: Relation with property path comments.user in entity was not found.

It works with v4.5.0

After some debugging, the TypeORM relation path used for user entity is: In v4.5.0: comments.user in v4.6.0: posts.comments.user

Here is the line where the error is thrown: function setJoins in packages/crud-typeorm/src/typeorm-crud.service.ts

builder[relationType](allowedRelation.path, alias);

I don’t know if it can be fixed easily or not, though.

Thanks for your feedback!

[jbrousseau]

Oh you’re right, thanks for your feedback. I’ve fixed it like that:

@Crud(
[...]
query: {
        join: {
            posts: {}
            posts.comments: { alias: 'postsComments'}
            posts.comments.user: { alias: 'postsCommentsUser'}
       }
})
export class PostsController {

With the HTTP GET that remains the same. Thanks!

[jeffreyschultz]

Even with the alias I am still getting this error.

Update:

I had to add an alias to ‘sections’, ‘sections.comments’, and ‘sections.comment.replies’, and not just ‘sections.comments’ and ‘sections.comment.replies’.

I am not sure, but this might be a bug in typeorm. I see that instead of breaking down the nested relation into multiple joins with aliases, the entire nested path is passed to Typeorm, and the cause of this issue.

This call to findRelationWithPropertyPath(this.relationPropertyPath) fails with this.relationPropertyPath being comments.replies. I would think that if you are searching within the parent alias, that it would be able to find comments.replies, unless it isn’t capable of handling that level of nesting.

Further investigation, that call to findRelationWithPropertyPath(this.relationPropertyPath) is not capable of handling the nesting. In the screen shot, this.relations only contains propertyPaths like sections, or comments–nothing like comments.replies, so this call returns nothing.

Update:

It seems this is by design in Typeorm. It wants you to turn that nesting into multiple joins with multiple aliases, such as the snippet below.

const user = await this.repo
      .createQueryBuilder('user')
      .innerJoinAndSelect('user.accounts', 'accounts')
      .leftJoinAndSelect('accounts.expenses', 'expenses')
      .leftJoinAndSelect('expenses.projects', 'projects')
      .where('user.id=:user_id')
      .setParameter('user_id', id)
      .getOne()

Here are the changes I ended up making to @Crud, and maybe its because I didn’t completely know how the aliases affected the other joins, but now it makes sense. It’s a mess right now, but Take note of how I am chaining the joins together with the aliases: sections.comments becomes sections_comments, and sections.comments.replies becomes sections_comments.replies, and so on.

    query: {
      filter: {
        'comments.parentId': {
          $eq: null
        }
      },
      join: {
        package: {
          eager: true
        },
        'package.organizations': {
          eager: true
        },
        owner: {
          eager: true,
          allow: allowedUserFields
        },
        editor: {
          eager: true,
          allow: allowedUserFields
        },
        createdBy: {
          eager: true,
          allow: allowedUserFields
        },
        status: {
          eager: true
        },
        forms: {
          eager: true
        },
        'forms.fields': {
          eager: true
        },
        groups: {
          eager: true
        },
        sections: {
          eager: true
        },
        'sections.parent': {
          eager: true
        },
        'sections.lockedBy': {
          eager: true,
          allow: allowedUserFields
        },
        'sections.comments': {
          alias: 'comments',
          eager: true
        },
        'comments.owner': {
          alias: 'comments_owner',
          eager: true,
          allow: allowedUserFields
        },
        'comments.replies': {
          alias: 'comments_replies',
          eager: true
        },
        'comments_replies.owner': {
          alias: 'comments_replies_owner',
          eager: true,
          allow: allowedUserFields
        },
        'sections.versions': {
          alias: 'versions',
          eager: true
        },
        'sections.history': {
          alias: 'history',
          eager: true
        }
      }
    }

Sorry for the length of this comment, but I am working late on some code needed for tomorrow.