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mongodb+aggregation - delete the upper level in the document

Analeea last edited by
I've got a collection of document types:
```
{fields:{_id:1, f1:10, f2:"репа", f3:200}, computedFields:{id:1}},
{fields:{_id:2, f1:10, f2:"репа", f3:200}, computedFields:{id:2}},
...
```
Inside the cadet (pipeline), I need to transform every document into:
```
{_id:1, f1:10, f2:"репа", f3:200, id:1},
{_id:2, f1:10, f2:"репа", f3:200, id:2},
...
```
I mean, we need to get rid of the top level by leaving the bottom.
Please tell me how to do this.
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1 Reply Last reply
Mystic last edited by
Since fields have unique identifiers, you can use the method https://docs.mongodb.org/manual/reference/method/db.collection.distinct/#db.collection.distinct :
```
SomeModel.distinct("fields")
```
This code will return the list. unique facilities fields of all collection facilities SomeModel♪ If you need a repetition, distinct It won't help.
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Solved by adding this line to the code: {$match: {cast:{$ne:"Undefined"}}}, And there'd be something: db.actors.aggregate([ {$match: {cast:{$ne:"Undefined"}}}, {$group : {_id: "$cast", total : {$sum: 1 }}}, {$sort:{total:-1}}, {$limit:5}]) Thank you.
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The problem is how you intend to make the relationship between models.I'm going to make some assumptions since you don't provide much information about the model. Genre and model Author.PROBLEMAYou want to relate 1 model (Book) of Mongoose with 2 other models also of Mongoose (Author and Genre) also wish to add that relationship whenever a new type document is created Book to the collection books from MongoDB. 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C http://mongoosejs.com/docs/index.html :Kitten.find({ name: /^Fluff/ }, callback);This performs a search for all documents with a name property that begins with Fluff and returns the result as an array of kittens to the callback.The only thing with no idea what the object callsback is-- maybe there's no function to drink.I don't know what to do. http://mongoosejs.com/docs/queries.html

mongodb+aggregation - delete the upper level in the document

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