mongodb - Mongo filter results by distinct field -

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I use this rugby driver to mow:

I have many documents in such a collection Are: 

  {"_productId" => 10 ....} {"_productId" => 10 ....} {"_productId" => 12 ....}

What does it mean to get all the documents with a specific "_productId", I mean I want to take the first and last collection items in this example.

@ db ['archive']. Specific ('_ Product ID')


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