How to set cursor for aggregation in mongoose?
[options.useMongooseAggCursor] “Boolean” uses an experimental mongoose-specific aggregation cursor (for eachAsync() and other query cursor semantics) Sets the cursor option for the aggregation query (ignored for < 2.6.0). Note the different syntax below: .exec() returns a cursor object and a callback is not required.
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How to return mongoose results from FIND METHOD?
}); Makes all mongoose methods (and their models) available as functions that return promises, with the Async suffix ( .exec() becomes .execAsync(), and so on). The .promisifyAll() method is almost universal in the Node.JS world: you can use it on anything that provides asynchronous functions that take the callback as their last argument.
What is the aggregation function in mongoose shell?
An introduction to the mongoose aggregate. Mongoose’s aggregate() function is how you use MongoDB’s aggregation framework with Mongoose. Mongoose’s aggregate() is a slim wrapper, so any aggregation query that works in the MongoDB shell should work in Mongoose without any changes.
How does the $match stage work in mongoose?
The $match stage filters out documents that do not match the given filter parameter, similar to the filters for Mongoose’s find() function. Aggregations can do much more than filter documents. You can also use the aggregation framework to transform documents. For example, the $group stage behaves like a reduce() function.
Why do the result fields appear undefined in mongoose?
If you don’t initialize or haven’t set a title. You will get undefined. The object is returned by mongoose collection.find( {}), but maybe you are right. Maybe there’s something wrong with my TextController initialization – tippenein Sep 10 ’15 at 10:04
When does the aggregate return an empty cursor in MongoDB?
A cursor to the documents produced by the final stage of the aggregation pipeline operation, or if you include the explain option, the document that provides details about the processing of the aggregation operation. If the pipeline includes the $out operator, the add() returns an empty cursor.
What happens when you prefix a string in mongoose?
If you are passing a string, Mongoose will prepend ‘$’ if the specified field does not start with ‘$’. If you are passing an object, the strings in your expression will not be modified. Add a new custom $sample operator to this aggregate pipeline. Helper for the $search stage of Atlas Text Search.