Combine two mongo aggregate query results into one - mongodb

Question

I have two mongo aggregate pipelines that output results. Now I want combine these two pipelines to have a singular output.
Please find below sample collection.
[
{
_id: "ddfdfdfdggfgfgsg",
rate: "3323",
quantity_packs: "343",
shop_name: "Whole Foods",
sku: "20"
manufacturer_name: "Unilever"
},
{
_id: "ddfdfdfsdsds",
rate: "434",
quantity_packs: "453",
shop_name: "Carrefour",
sku: "200"
manufacturer_name: "Unilever"
},
{
_id: "dfdfdgcvgfgfvvv",
rate: "343",
quantity_packs: "23",
shop_name: "Target",
manufacturer_name: "Beirsdorf"
sku: "34"
}
]
Please find below my queries.
First Query
db.collection.aggregate([
{
$match: {
manufacturer_name: {
$in: [ "unilever" ]
}
}
},
{
$group: {
_id: {
"Shop Name": "$shop_name"
},
"total_sku": {
"$addToSet": "$sku"
},
"annual_cost": {
$sum: {
$cond: [
{
$eq: ["$manufacturer_name", "unilever"]
},
{
"$toDouble": "$rate"
},
0
]
}
},
"annual_qty": {
$sum: {
"$toDouble": "$annual_qty"
}
}
}
},
{
$project: {
"sku count": {
"$size": "$total_sku"
},
"Annual Cost WO GST": {
$multiply: [ "$annual_cost", "$annual_qty" ]
},
}
},
])
Result of First Query
[
{
_id: { 'Hospital Name': '7AM mart' },
'sku count': 29,
'Annual Cost WO GST': 79968887.67999999
},
{
_id: { 'Shop Name': 'Apex' },
'sku count': 20,
'Annual Cost WO GST': 1779192666.96
}
]
Second Query
db.collection.aggregate([
{
$match: {
$expr: {
$ne: ["$manufacturer_name", "unilever"]
}
}
},
{
$group: {
_id: {
"Shop Name": "$shop_name"
},
"annual_cost_wo_gst_wo_manu": {
$sum: {
"$toDouble": "$rate"
}
},
"annual_qty": {
$sum: {
"$toDouble": "$annual_qty"
}
}
}
},
{
$project: {
"Ann Cost For Other Manufacturers": {
$multiply: ["$annual_cost_wo_gst_wo_manu", "$annual_qty"]
},
}
}
])
Result of Second Query
[
{
_id: { 'Hospital Name': 'Apex' },
'Ann Cost For Other Manufacturers': 25246715130525.273
},
{
_id: { 'Hospital Name': '7AM Mart' },
'Ann Cost For Other Manufacturers': 1347701834351.495
}
]
As mentioned above, I somehow want to combine to results by correctly mapping the items.
Intended Result
[
{
_id: { 'Hospital Name': '7AM mart' },
'sku count': 29,
'Annual Cost WO GST': 79968887.67999999
'Ann Cost For Other Manufacturers': 1347701834351.495
},
{
_id: { 'Shop Name': 'Apex' },
'sku count': 20,
'Annual Cost WO GST': 1779192666.96
'Ann Cost For Other Manufacturers': 25246715130525.273
}
]

Answer 1

Your 2 queries do not quite produce your stated outputs. Nevertheless, you could first perform uncorrelated $lookup to perform your second query, storing the result of your secondary query in a field/object. Then you can continue your first query. Finally extract the result of secondary query from the previously stored field/object.
Here is a Mongo playground with some modifications to your original examples for your reference.