I am facing a problem with MongoDB query. Our collection named is products and the data is placed something like this.
{
"_id":"61b823681975ba537915cb0c",
"salesInfo":{
"_id":"61b823681975ba537915c23c",
"salesDate":[
{
"_id":"61b3aa4a7b04b30cd0a76b06",
"salesQuantity":100,
"soldPieces":36,
"holdPieces":0
},
{
"_id":"61b3aa4a7b04b30cd0a75506",
"salesQuantity":100,
"soldPieces":36,
"holdPieces":0
}
]
}
}
I want to add a new field named percentageSold inside an array of objects, and the value should be the calculation of the following formula ((soldPieces + holdPieces) / salesQuantity * 100).
My query is this but it is returning null for the percentageSold property.
db.products.aggregate( [
{
$addFields: {
"salesInfo.salesDate.percentageSold": {$divide: [{$add: ["$salesDate.soldPieces", "$salesDate.holdPieces"]}, {$multiply: ["$salesDate.salesQuantity", 100]}]}
}
}
])
As salesInfo.salesDate is an array field, you need to to use array operator like $map to perform element-wise operation.
db.products.aggregate([
{
$addFields: {
"salesInfo.salesDate": {
"$map": {
"input": "$salesInfo.salesDate",
"as": "s",
"in": {
"_id": "$$s._id",
"salesQuantity": "$$s.salesQuantity",
"soldPieces": "$$s.soldPieces",
"holdPieces": "$$s.holdPieces",
"percentageSold": {
$divide: [
{
$add: [
"$$s.soldPieces",
"$$s.holdPieces"
]
},
{
$multiply: [
"$$s.salesQuantity",
100
]
}
]
}
}
}
}
}
}
])
Here is the Mongo playground for your reference.