how to match both fields are not exist

Question

I was trying to use $and to express both fields are empty
Here is the code

    db.tweets_v2.aggregate({
      {match:{$and:[{replyto_id:$exist:false},{replyto_id:$exist:false}]}
    });

It still did not work, could you please give me the full of the code? thanks — Jay Park, Sep 09 '20 at 17:31

score 2 · Accepted Answer · answered Sep 09 '20 at 17:36

There are few fixes,

$exist should be $exists
missed {} brackets before and after in $exists
match should be $match
aggregation stages start from [] not {}

db.tweets_v2.aggregate([
  {
    $match: {
      $and: [
        { replyto_id: { $exists: false } },
        { replyfrom_id: { $exists: false } } // change your second field name
      ]
    }
  }
])

Playground

score 1 · Answer 2 · answered Sep 09 '20 at 19:00

1

Actually the $and is not needed, this one will also work:

db.tweets_v2.aggregate([
  {
    $match: {
        replyto_id: { $exists: false } ,
        replyfrom_id: { $exists: false }
    }
  }
])

answered Sep 09 '20 at 19:00

Wernfried Domscheit

54,457
9
76
110

Thank you for reminding, this one is also really helpful as well. – Jay Park Sep 10 '20 at 01:05

how to match both fields are not exist

2 Answers2