So I have records in a mongo database which are of this format (just an example):
{
_id: 1,
name: "some name1",
description: "some description1",
parameters: [
{
name: "param name1",
type: "param type1",
default: "default value1"
},
{
name: "param name2",
type: "param type2",
default: "default value2"
}
]
.
.
.
}
In my program I am performing this aggregation on the records:
{
'$project': {
'title': '$name,
'description': True,
'parameters': {
'name': True,
'parameter_type': '$parameters.type',
'value': '$parameters.default'
}
}
}
The result I was trying to get:
{
_id: 1,
title: 'some name1',
description: "some description1",
parameters: [
{
name: "param name1",
parameter_type: "param type1",
value: "default value1"
},
{
name: "param name2",
parameter_type: "param type2",
value: "default value2"
}
]
}
Instead I got:
{
_id: 1,
title: 'some name1',
description: "some description1",
parameters: [
{
name: "param name1",
parameter_type: ["param type1", "param type2"],
value: ["default value1", "default value2"]
}
]
}
All am I trying to do is change the field names for the objects in the parameters list. I have tried looking through the MongoDB docs but I have not been able to find a way to do what I need.
$unwind Deconstructs an array field from the input documents and group them back with desired projection.
Demo - https://mongoplayground.net/p/-pIPbSarfyx
db.collection.aggregate([
{
"$unwind": "$parameters"
},
{
"$group": {
"_id": "$_id",
"name": {
"$first": "$name"
},
"description": {
"$first": "$description"
},
"parameters": {
"$push": {
"name": "$parameters.name",
"parameter_type": "$parameters.type",
"value": "$parameters.default"
}
},
}
}
])