MongoDB join two collections with between clause - mongodb

Question

There is a collection "Printers":
{
"_id" : ObjectId("5cc02f9b9931de72296ba6c2"),
"model" : "Xerox WorkCentre 3315",
"serial" : "3255498494",
"date" : ISODate("2019-04-25T08:57:48.001+0000"),
"pages" : NumberInt(4868),
"location" : "New location",
"ip" : "10.159.0.35",
"ip_int" : NumberInt(178192419)
}
and "Branches" collection:
{
"_id" : ObjectId("5cb4799b8c0cfe35e4a4c266"),
"name" : "Office 1",
"ip_start" : NumberLong(178192384),
"ip_end" : NumberLong(178194431)
}
// ----------------------------------------------
{
"_id" : ObjectId("5cb479e68c0cfe35e4a4c269"),
"name" : "Office 2",
"ip_start" : NumberLong(3232258048),
"ip_end" : NumberLong(3232258303)
}
"Branches" collection contains ip addresses converted into integer value, i.e. 192.168.0.1 is 3232235521. Each record in Branches describes subnet.
Each printer located in one branch.
If printers.ip_int between branches record [ip_start;ip_end] then query should return all fields from Printer and one field "Name" from "Branches" collection.
How can i do this?

Answer 1

You need a lookup with custom pipeline where you can specify "between" condition:
db.Branches.aggregate([
{
$lookup: {
from: "Printers",
let: { ip_start: "$ip_start", ip_end: "$ip_end" },
pipeline: [
{
$match: {
$expr: {
$and: [
{ "$gte": [ "$ip_int", "$$ip_start" ] },
{ "$lte": [ "$ip_int", "$$ip_end" ] },
]
}
}
}
],
as: "Printers"
}
}
])

Answer 2

db.getCollection("printers").aggregate(
[
{
"$lookup" : {
"from" : "branches",
"let" : {
"ip_int" : "$ip_int"
},
"pipeline" : [
{
"$match" : {
"$expr" : {
"$and" : [{"$gte" : ["$$ip_int", "$ip_start"]},
{ "$lte" : ["$$ip_int", "$ip_end"]}
]
}
}
}
], "as" : "Printers"
}
},
{
"$sort" : {
"ip_int" : 1.0
}
},
{
"$unwind" : {
"path" : "$Printers"
}
},
{
"$addFields" : {
"filial" : "$Printers.name"
}
},
{
"$project" : {
"Printers" : false, "ip_int" : false
}
}
]);