Mongo aggregation framework match a given _id - database

Question

My model :
const scheduleTaskSchema = new Schema({
activity: { type: Object, required: true },
date: { type: Date, required: true },
crew: Object,
vehicle: Object,
pickups: Array,
details: String,
});
const ScheduleTaskModel = mongoose.model("schedule_task", scheduleTaskSchema),
and this aggregation pipeline :
let aggregation = [
{
$sort: {
"pickups.0.time": 1,
},
},
{
$group: {
_id: "$date",
tasks: { $push: "$$ROOT" },
},
},
{ $sort: { _id: -1 } },
];
if (hasDateQuery) {
aggregation.unshift({
$match: {
date: { $gte: new Date(start_date), $lte: new Date(end_date) },
},
});
} else {
aggregation.push({ $limit: 2 });
}
const scheduledTasksGroups = await ScheduleTaskModel.aggregate(aggregation);
the crew object can have arbitrary number of keys with this structure :
crew : {
drivers: [
{
_id: "656b1e9cf5b894a4f2v643bc",
name: "john"
},
{
_id: "567b1e9cf5b954a4f2c643bhh",
name: "bill"
}
],
officers: [
{
_id: "655b1e9cf5b6632a4f2c643jk",
name: "mark"
},
{
_id: "876b1e9af5b664a4f2c234bb",
name: "jane"
}
],
//...any number of keys that contain an array of objects that all have an _id
}
I'm looking for a way to return all documents (before sorting/grouping) that contain a given _id anywhere within the crew object without knowing which key to search,it can be many different keys that all contain an array of objects that all have an _id
Any ideas ?

Answer 1

You can use $objectToArray for this:
db.collection.aggregate([
{$addFields: {crewFilter: {$objectToArray: "$crew"}}},
{$set: {
crewFilter: {$size: {
$reduce: {
input: "$crewFilter",
initialValue: [],
in: {$concatArrays: [
"$$value",
{$filter: {
input: "$$this.v",
as: "member",
cond: {$eq: ["$$member._id", _id]}
}
}
]
}
}
}}
}},
{$match: {crewFilter: {$gt: 0}}}
])
See how it works on the playground example