Inserting many documents in collection, but only unique elements, based on specific field. MongoDB

I cannot seem to find an answer on this anywhere. I need the following:

Given an array of objects with the structure:

{    link: 'some-link',    rating: 25,    otherFields: '..',    ... }  I want to insert them into my collection. So I would just do insertMany... But I only want to insert those elements of the array that are unique, meaning that I do not want to insert objects with the field "link" being something that is already in my collection.  Meaning if my collection has the following documents:  {   _id: 'aldnsajsndasd',   link: 'bob',   rating: 34, } {    _id: 'annn',    link: 'ann',    rating: 45 } 

And I do the “update/insert” with the following array:

[{   link: 'joe',    rating: 10 },{   link: 'ann',   rating: 45 }, {   link: 'bob',   rating: 34 }, {   link: 'frank',   rating: 100 }] 

Only documents:

{   link: 'frank',   rating: 100 } {    link: 'joe',   rating: 10 } 

Would be inserted in my collection