CODEWITHSUNDEEP
node.jsmongodbmongoose
ShobiDobi
ShobiDobi

Reputation: 246

Nested queries in Mongo DB using mongoose and NodeJS

I have this two Collections that I use, I need to query from one of the collection using params from the first collection

Collection expamples:

Collection 1 :{
id: 1234,
lastDate : "2020-09-10T08:30:14.960+00:00"
}

Collection 2 :{
site : 1234,
date : "2020-09-10T08:30:14.960+00:00"
}

I need to get the id and "lastDate" from Collection 1 and use it to query on Collection 2

sorry for bad explanation tell if need more info or anything

ADDED SQL equivalent

SELECT * FROM collection2 
WHERE site IN (SELECT id FROM collection1) and
 date IN (SELECT lastDate FROM collection1);

Upvotes: 0

Views: 159

Answers (3)

Tahero
Tahero

Reputation: 328

 db.FIRST_COLLECTION.aggregate([
  {
    $lookup: {
      from: "FIRST_COLLECTION",
      localField: "id", // local field of first collection
      foreignField: "site", // foreign field at second collection
      as: "liste",
    },
  },
  { $unwind: "$liste" },
  {
    $group: {
      _id: "$site",
      data: {
        $addToSet: {
          site: $site,
          date: $date,
        },
      },
    },
  },
]);

I invite you to read more about Aggregation

Upvotes: 0

Kuldeep Mishra
Kuldeep Mishra

Reputation: 4040

 let params  = {_id:1}
 let data = await Collection1.aggregate([
    {$match:params},
   {
      $lookup: {
        from: "collection2",
        localField: "$collection1datefield",
        foreignField: "$collection2datefield",
        as: "collection2Object"
      }
   }
  ])

Upvotes: 1

Hemant
Hemant

Reputation: 95

If you have done referencing into the first collection then you can use simple query i.e

const query = await Collection1.findOne({id: req.params.id}).populate('site lastDate');

Upvotes: 0

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