aggregate function in mongodb code example
Example 1: how to write the aggragation in mongodb
> db.mycol.aggregate([{$group : {_id : "$by_user", num_tutorial : {$sum : 1}}}])
{ "_id" : "tutorials point", "num_tutorial" : 2 }
{ "_id" : "Neo4j", "num_tutorial" : 1 }
>
Example 2: how to use mongoose aggregate
const agg = Model.aggregate([{ $match: { age: { $gte: 25 } } }]);
for await (const doc of agg) {
console.log(doc.name);
}
Example 3: how to use mongoose aggregate
new Aggregate([{ $match: { _id: '00000000000000000000000a' } }]);
// Do this instead to cast to an ObjectId
new Aggregate([{ $match: { _id: mongoose.Types.ObjectId('00000000000000000000000a') } }]);