Mongoose aggregate pipeline date greater than query with bson varible - node.js

Question

Actually, I am raising this question after trying previous questions answers. but, I don't find any clue that's why I am asking
Trying to achieve:
In mongoose aggregation, I am using pipeline aggregation to get documents from the collection by the following query
$match: {
$and: [
{
$expr: {
$eq: ["$device_id", "$$device_id"]
}
},
{
date: {
"$gte": "$billing_cycle_startdate",
"$lte": endOfDay
}
}
]
}
billing_cycle_startdate will be : 2020-12-31T00:00:00.000Z by following query
{
$addFields: {
billing_cycle_startdate: {
$concat: [
year, "-", month, "-", "$device_details.billing_cycle"
]
},
}
},
{ $set: { billing_cycle_startdate: { $toDate: "$billing_cycle_startdate" } }},
but this query returns empty results
if I run
{
date: {
"$gte": new Date("2020-12-31T00:00:00.000Z"),
"$lte": endOfDay
}
}
it returns results as expected
is there is any other way to convert 2020-12-31T00:00:00.000Z to queryable format without using new Date() function and also want to know what is the difference between 2020-12-31T00:00:00.000Z and new Date("2020-12-31T00:00:00.000Z")
There is any other way to achieve this query??
Thanks in advance..!

Answer 1

Finally, after a few days of suffering, I found what's wrong with my query
I just forget to use let syntax in my pipeline to specify a variable which is billing_cycle_startdate and forget to use it in the pipeline field stage
The pipeline cannot directly access the input document fields.
Instead, first, define the variables for the input document fields,
and then reference the variables in the stages in the pipeline.
for more: click here
then I changed my query as follows
{
$lookup: {
from: "name",
let: {
device_id: "$budget.device",
billing_cycle_startdate: "$billing_cycle_startdate"
},
pipeline: [
{
$match: {
$and: [
{
$expr: {
$eq: ["$device_id", "$$device_id"]
}
},
{
$and: [
{
$expr: {
$gte: ["$date", "$$billing_cycle_startdate"],
},
},
{
$expr: {
$lte: ["$date", endOfDay],
}
}
]
}
]
}
}
],
as: "dailyenergylogs"
}
},