How can I get only specific object from nested array mongodb - mongodb

Question

I'm using mongoDB with PHP. I know how to get the document based on product_id, but I need only a specific object from the whole document, I don't know how to get only specific object from nested array based on product_id.
for ex. My expected output is:
products": [
{
"product_id": 547,
"name": "cola",
"quantity": 24
}
]
then make some changes on object p.s update the quantity then update it to the database.
My collection looks like
"_id": {
"$oid": "62ed30855836b16fd38a00b9"
},
"name": "drink",
"products": [
{
"product_id": 547,
"name": "cola",
"quantity": 24
},
{
"product_id": 984,
"name": "fanta",
"quantity": 42
},
{
"product_id": 404,
"name": "sprite",
"quantity": 12
},
{
"product_id": 854,
"name": "water",
"quantity": 35
}
]
}

Answer 1

Try this:
db.getCollection('test').aggregate([
{
"$unwind": "$products"
},
{
"$match": {
"products.product_id": 547
}
},
{
"$replaceRoot": {
"newRoot": {
"$mergeObjects": [
"$$ROOT",
"$products"
]
}
}
},
{
"$project": {
"products": 0
}
}
])
The query gives the following output:
{
"name" : "cola",
"product_id" : 547,
"quantity" : 24
}