[CRUD Writable Views] It's not clear how to configure the pipeline for a one-to-many relation (multilookup)

[alexBonadei]

Which section?

Marketplace

Which is the version?

.

Description

Hi, I'm having troubles when setting up a writable view.

I have the orders collection where there is a field called dishes which is an array of strings representing the ids of the ordered dishes:

{
_id: ObjectId('.....'),
dishes: ['652552e4fe1a7dade996a730', '652552e4fe1a7dade996a731']
}

I wrote a pipeline for the view that correctly returns this:

{
_id: ObjectId('.....'),
"dishes": [
        {
          "value":"652552e4fe1a7dade996a730",
          "name": "dish1"
        },
        {
          "value":"652552e4fe1a7dade996a731",
          "name": "dish2"
        }
    ]
}

However the POST does not work as I expect.

The docs states this:
Have at least one $lookup step in the view pipeline followed by $unwind to make sure only one object it is returned;

But after the lookup step I don't need to unwind, because then I'll be forced to group them back.
Probably the pipeline I wrote is not compatible.

My pipeline performs these steps:

1. $addFields: It basically converts the strings in the dishes array in objectIds for performing the lookup
2. $lookup: performs the lookup
3. $project

Am I missing something? Thank you in advance

Actual Outcome

No response

Expected Outcome

No response

[danibix95]

Hi @alexBonadei! We acknowledged the unclear documentation regarding Writable Views and the fact that multi-lookup was not properly working.

Consequently, we implemented a fix for configuring multi-lookups in aggregation pipeline and reviewed the documentation. It is available in the new CRUD Service version, v6.9.3.
However, we recommend to upgrade to version v6.9.4, which also includes a startup improvement when indexes should be created.