How to lookup with localField and foreignField more than one in MongoDB

  Today I will try to share information on "How to lookup with localField and foreignField more than one in MongoDB", This information may be rarely short because just seeing a piece of code only. But this code work for MongoDB current version.

So let's see a piece of code below  :

  db.detailactivities.aggregate([{$lookup:

    {

      from: "activities",

      localField: "user_id",

      localField: "activity_id",

      foreignField: "user_id",

      foreignField: "_id",

     as: "products"

    }

  }]);

Output/result of my project only:

  {

    _id: ObjectId("6493ef3c6ee4fdb45bb6e4db"),

    user_id: ObjectId("648aecc8ea9841c8bec570a7"),

    activity_id: ObjectId("6491a39cbb3be69d2f793ae7"),

    doing_activity: 'doo',

    description: 'd',

    created: 2023-06-22T06:50:36.199Z,

    __v: 0,

    products: [

      {

        _id: ObjectId("6491a39cbb3be69d2f793ae7"),

        user_id: '648aecc8ea9841c8bec570a7',

        activity: 'Blogger',

        description: 'Blogger',

        created: 2023-06-20T13:03:24.682Z,

        __v: 0

      }

    ]

  }

Ok, that is just a little information, hope can help you. Another question please leave comments below. Thanks for your visiting my blog.