Agregation pipeline with Relational Pointer

Client SDKs JavaScript SDK
#1

±-------------------------------------------------------+

| Company class |

±---------±--------------±----------±----------------+
| objectId | category (Category Pointer) | name | subCategory (subCategory Relation) |
±---------±--------------±----------±----------------+

±----------------------------------------------------------------------------------+
| SubCategory class |
±---------±-------------------------±--------------±----------±----------------+
| objectId | name | category (Category Pointer)|
±---------±-------------------------±--------------±----------±----------------+

Relation between of Company and SubCategory is mant-to-many

I want to get all companies with belongs to specific category and match specific subcategory using lookup aggregation query.

Please help me. Thanks all.

#2

Could you please share what you’ve tried so far?

#3

var pipeline = [
{ match: { status: true } },
{ match: { _p_category: ‘Category$’ + categoryId } },
{
project: {
brand: 1,
discount: 1,
logo: 1,
status: 1,
main: 1,
objPointer: { ‘$concat’: [‘Company$’, ‘$_id’] }
}
},
{
lookup: {
from: “CompanyQualification”,
localField: “objPointer”,
foreignField: “_p_company”,
as: “qualifications”
}
},
{
lookup: {
from: “Shop”,
let: { companyID: “$objPointer”, cityID: “City$” + cityId, state: true },
pipeline: [
{
$match:
{
$expr:
{
$and:
[
{ $eq: ["$$companyID", “$_p_company”] },
{ $eq: ["$$cityID", “$_p_city”] },
{ $eq: ["$$state", “$status”] }
]
}
}
}
],
as: “shops”
}
},
{
match: { shops: { $ne: } }
},
{ sort: { main: -1 } },
];

This is the current pipeline, i need to match a specific subCategory in the Company but this is the type Relation not Pointer so i don`t know how can i do it?

#4

In the case of a relation your database have a collection called _Join:subCategory:Company with a owningId field containing the if of the Company object and a relatedId field containing the id of the associated SubCategory object. You need to adjust your aggregate steps accordingly.

#5

But, It is possible to do a lookup with this collections? seems to not work.

#6

Yes. It should be possible.