How to perform a full match search on an array?

Question

MongoDB

There is a model

Schema({
  members: [
    {
      type: String,
      required: true,
      ref: "User"
    }
  ],
  createdAt: {
    type: Date,
    default: Date.now(),
    required: true
  },
  lastMessage: {
    message: {
      type: String,
      required: true
    },
    from: {
      type: String,
      required: true
    },
    createdAt: {
      type: Date,
      required: true
    }
  },
  messages: [
    {
      createdAt: {
        type: Date,
        required: true
      },
      message: {
        type: String,
        required: true
      },
      from: {
        type: String,
        ref: "User",
        required: true
      }
    }
  ]
});

This is the code I use for searching

Chats.countDocuments(
      {
        members: {
          $in: ["userIdOne", "userIdTwo"]
        }
      },
      cb
    )

The problem is that the search does not follow the exact match of the $in parameter . If there are several documents where members contains at least one userId... parameter from $in , then the search will show this.

What I need is that if I set two parameters, then I need to display only those documents where there are only these two parameters, that is, by complete coincidence.

Answer 1

Found a solution.
Should use $all instead of $in

Chats.countDocuments(
  {
    members: {
      $all: ["userIdOne", "userIdTwo"]
    }
  },
  cb
)