I have a collection in database that I am trying to retrieve some data from it , the query is working fine when $orderID has string elements , but is failing when $orderID has some numbers in array , and it is throwing
query failed: (Location40395) PlanExecutor error during aggregation :: caused by :: $arrayToObject requires an array of key-value pairs, where the key must be of type string. Found key type: double
I think there must be some old data when we were saving orderID as a number so that is why it is failing from some range of dates
Query
{
"Order_Details": {
"$map": {
"input": {
"$objectToArray": {
"$arrayToObject": {
"$zip": {
"inputs": [
"$orderID",
"$total_value_of_order"
]
}
}
}
},
"as": "el",
"in": {
"orderID": "$$el.k",
"total_value_of_order": "$$el.v"
}
}
}
}
I am trying to typecast el.k to string I am using $toString but can't seem to work , the way I am trying it is
{
"as": "el",
"in": {
"orderID": {
"$toString": "$$el.k"
},
"total_value_of_order": "$$el.v"
}
}
Example collection
[
{
"_id": ObjectId("5e529ee5f8647eb59e5620a2"),
"visitID": "dVmy7flXFHzzkn9HiMt8IoWvthoTZW",
"date": ISODate("2022-02-08T16:29:13.413Z"),
"control": true,
"orderID": [
122343242
],
"target": "test",
"total_value_of_order": [
60
]
}
]
You are close, the approach is fine. you just have a couple of syntax issues.
The major thing that needs to change is the input for $arrayToObject, currently your input looks like this:
[[number, number], [number, number]]
However $arrayToObject expects input in a certain format:
[{k: string, v: value}]
So this it what we'll add, like so:
db.collection.aggregate([
{
$project: {
"Order_Details": {
"$map": {
"input": {
"$objectToArray": {
"$arrayToObject": {
$map: {
input: {
"$zip": {
"inputs": [
"$orderID",
"$total_value_of_order"
]
}
},
in: {
k: {
$toString: {
"$arrayElemAt": [
"$$this",
0
]
}
},
v: {
"$arrayElemAt": [
"$$this",
1
]
}
}
}
}
}
},
"as": "el",
"in": {
"orderID": "$$el.v",
"total_value_of_order": "$$el.k"
}
}
}
}
}
])
Notice the "orderid" format changes to string which affects it's structure, I recommend just switching between the k and v in the pipeline, like this