Triple relation lookup in MongoDB - mongodb

Question

I have tried to solve this one but its WAY over my Mongo skill level.
I hope there are some hardcore Mongo wizards who have an idea :-)
I would like to make a result where
db.getCollection('invoice').find({
dueDate: {
$gte:148000000,
$lt: 149000000
}
})
This is the "invoice" table....
invoice
{
"_id" : "KLKIU",
"invoiceNumber" : 1,
"bookingId" : "0J0DR",
"dueDate" : "148100000",
"account" : "aaaaaaaaaa",
"invoiceLines" : [
{
"lineText" : "Booking fee",
"amount" : 1000
},
{
"lineText" : "Discount",
"amount" : -200
},
{
"lineText" : "Whatever extra",
"amount" : 400
}
]
}
this is the result
{
"_id" : "KLKIU",
"invoiceNumber" : 1,
"bookingId" : "0J0DR",
"dueDate" : "148100000",
"account" : "aaaaaaaaaa",
"invoiceLines" : [
{
"lineText" : "Booking fee",
"amount" : 1000
},
{
"lineText" : "Discount",
"amount" : -200
},
{
"lineText" : "Whatever extra",
"amount" : 400
}
],
"propertyName" : "Atlantis Condo",
}
please notice the "propertyName" at the bottom
it needs to lookup and add
"propertyName" : "Atlantis Condo",
which will be done like this
db.getCollection('booking').find({
booking._id: invoice.bookingId
})
and then
db.getCollection('property').find({
property._id: booking:propertyId
})
These are the two tables:
Booking
{
"_id" : "0J0DR",
"propertyId" : "58669471869659d70b424ea7",
}
Property
{
"_id" : "58669471869659d70b424ea7",
"propertyName" : "Atlantis Condo",
}
Hope someone can figure this out - right now im doing some horrible sequential loops, and with big amounts of data thats really slow.

Answer 1

You can try below aggregation.
$lookup's to join to Booking and Property collection.
$unwind to flatten the booking array output from $lookup for joining on local field to Property collection.
$addFields to project the propertyName field.
$project to exclude the fields from referenced collection.
db.getCollection('invoice').aggregate([{
$match: {
"dueDate": {
$gte: 148000000,
$lt: 149000000
}
}
}, {
$lookup: {
from: "Booking",
localField: "bookingId",
foreignField: "_id",
as: "booking"
}
}, {
$unwind: "$booking"
}, {
$lookup: {
from: "Property",
localField: "booking.propertyId",
foreignField: "_id",
as: "property"
}
}, {
$unwind: "$property"
}, {
$addFields: {
"propertyName": "$property.propertyName"
}
}, {
$project: {
"booking": 0
}
}, {
$project: {
"property": 0
}
}])