MongoDb and Golang - $group and $match

Question

I am trying to $match my data after $group but it does not work. I have db with jobs. Every job has {id, batchId(a few jobs can belong to one batch), createdAt, finishedAt}.

I cant understand why I am getting empty result. I need to get the groups of the jobs with the same batchId that were created before CreatedAtTo parameter. For saving date I used unix timestamp (so it is an integer)

My solution:

group := bson.M{
    "$group": bson.M{
        "_id":   "$batchid",
        "btime": bson.M{"$max": "$createdAt"},
        "doc":   bson.M{"$push": "$$ROOT"},
    },
}

match := bson.M{
    "$match": bson.M{
        "btime": bson.M{
            "$lte": CreatedAtTo},
    },
}

sort := bson.M{"$sort": bson.M{"btime": -1}}
limit := bson.M{"$limit": 1}

pipeline := []bson.M{group, match, sort, limit}

If I comment $match part it works, but not all together. And tried to perform in robo 3t. It works as well

    db.getCollection('jobs').aggregate(
    [
    {$group:{
        "_id":"$batchId",
        btime: { $max: "$createdAt"},
        bItems: { $push: "$$CURRENT" }
    }},
    {$match:{"btime": {"$lte": 10}}},
    {$sort:{"btime": -1}},
    {$limit:1},
    ])

Am I missing something ?

Answer 1

It should work, make sure all your field is a valid date or use $toDate

db.collection.aggregate([
  {
    $group: {
      _id: "$batchid",
      btime: {
        $max: "$createdAt"
      },
      doc: {
        $push: "$$ROOT"
      }
    }
  },
  {
    $match: {
      btime: {
        $gt: "2021-07-01T11:23:25.184Z"
      }
    }
  }
])

mongoplayground