MongoDb aggregation $match error : "Arguments must be aggregate pipeline operators"
Solution 1
Pipeline stages are separate BSON documents in the array:
games.aggregate([
{ $match: { 'game_user_id' : '12345789' } },
{ $group: {
_id: '$id',
game_total: { $sum: '$game_amount'},
game_total_profit: { $sum: '$game_profit'}}
}}
]).exec(function ( e, d ) {
console.log( d )
});
So the Array or []
bracket notation in JavaScript means it expects a "list" to be provided. This means a list of "documents" which are generally specified in JSON notation with {}
braces.
Solution 2
Another possible reason could be due to an empty object {} inside the pipeline. It can happen if you are using any conditional stages in the pipeline.
eg:
const pipeline = []:
.....
.....
let sort = {}
if(params.sort){
sort = { $sort: { popularity: -1 } }
}
pipeline.push(sort)
This will cause the same error "Arguments must be aggregate pipeline operators"
Instead you can use something like this:
let sort;
if(params.sort){
sort = { $sort: { popularity: -1 } }
}
pipeline.concat(sort? [sort] : [])
Solution 3
const stats = await Tour.aggregate([
{
$match: { ratingsAvarage: { $gte: 4.5 } }
},
{
$group: {
_id: null,
avgRating: { $avg: '$ratingsAvarage' }
}
}]
Make sure to separate the pipeline stages with as obj or {} inside the array. So $match and $group have to be inside an object.
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Comments
-
Lazy over 2 years
I can get all stats of the site with
aggregation
but I want to it for a certain user, like$where
.All stats:
games.aggregate([{ $group: { _id: '$id', game_total: { $sum: '$game_amount'}, game_total_profit: { $sum: '$game_profit'}} }]).exec(function ( e, d ) { console.log( d ) })
When I try to use
$match
operator, I'm getting error :games.aggregate([{ $match: { '$game_user_id' : '12345789' }, $group: { _id: '$id', game_total: { $sum: '$game_amount'}, game_total_profit: { $sum: '$game_profit'}} }]).exec(function ( e, d ) { console.log( d ) }) Arguments must be aggregate pipeline operators
What am I missing?
-
Lazy over 9 yearsI thank you. But when I queried for a user, I'm getting only
[]
. (When I delete content of$match
it's working (giving all stats).) -
Lazy over 9 yearsI just deleted the
$
from$game_user_id
and it worked, I will never understand mongodb.. Anyway thanks again.