Compare db 1 collection view with db 2 collection

Working with Data
1

hello, first topic on this forum, i’m a newbie with mongoDB
I’m trying to help someone who compares datas from mongoDB with Excel :thinking:

For example, i’ve got a collection “product” in database1 toImport

{ 
    "_id" : ObjectId("5eab18424e2cab4319beb772"), 
    "productLongKey" : "denisetienne", 
    "productName" : "denis"
}
{ 
    "_id" : ObjectId("5eabece9442fd473979da3bf"), 
    "productLongKey" : "raoulmarcel", 
    "productName" : "raoul"
}
{ 
    "productLongKey" : "denisgeorge", 
    "productName" : "denis", 
    "_id" : ObjectId("5eabf27f442fd473979da3db")
}

I have created a view to have a sort of productKey with the productLongKey -> “$substr” :

["$productLongKey", 
            0.0, 
            4.0
]

so i’ve got

{ 
    "_id" : "deni", 
    "productName" : "denis"
}
{ 
    "_id" : "raou", 
    "productName" : "raoul"
}

I need to compare my view with a collection product in database2
I must check that “_id” : “deni” = “productKey” : “deni”
And “productName” : “denis” = “productName” : “raoul”

I’m using Studio 3T but the software only compare collections not view with a collection.
I’have only access to database.

Could you help me ?

Thanks

Bertrand