MongoDB Aggregation $out
Aggregation $out
This aggregation stage writes the returned documents from the aggregation pipeline to a collection.
The $out stage must be the last stage of the aggregation pipeline.
Example
In this example, we are using the "sample_airbnb" database loaded from our sample data in the Intro to Aggregations section.
db.listingsAndReviews.aggregate([
{
$group: {
_id: "$property_type",
properties: {
$push: {
name: "$name",
accommodates: "$accommodates",
price: "$price",
},
},
},
},
{ $out: "properties_by_type" },
])
The first stage will group properties by the
property_type and include the name,
accommodates, and price fields for each.
The $out stage will create a new collection called
properties_by_type in the current database and write the resulting documents into that collection.
