Display field document in mongoDB after execute Query aggregate - mongodb

Question

This is an example of a data document
{
"_id" : ObjectId("5f437e7846103b2ad0fc5d7d"),
"order_no" : "O-200824-AGFJDQW",
"shipment_no" : "S-200824-AGWCRRM",
"member_id" : 2200140,
"ponta_id" : "9990010100280214",
"plu" : 14723,
"product_name" : "AQUA Air Mineral Botol Air Pet 600ml",
"qty" : 2,
"store_id" : "TD46",
"stock_on_hand" : 0,
"transaction_date" : ISODate("2020-08-24T08:28:29.931Z"),
"created_date" : ISODate("2020-08-24T08:46:48.441Z")
}
this is the data query that I run
var bulan = 12 //month is written with number. example: August = 8
db.log_stock_oos.aggregate([
{
$project: {
month: {
$month: '$transaction_date'
}
}
},
{
$match: {month: bulan}
}
]);
but the result is like this after I run the query
{
"_id" : ObjectId("5f44689607fe453fbfba433e"),
"month" : 12
}
how to make the output exactly like the document display that I attached above??
this is my reference

Answer 1

When you use the projection, its kind of if your value 1 then include the field, if your value 0 then exclude the field from the whole documents. Projection
You can do two things
Use the projection
db.collection.aggregate([
{
$project: {
month: {
$month: "$transaction_date"
},
order_no: 1,
shipment_no: 1,
member_id: 1,
//other fields like above with the value 1
}
},
// match stages
])
Use $addFields
use $addFields incited of $project in your code. If will create a filed if not exists in your document, else it will overwrite the field