Querying with MongoDB subelement?

MongoDBDatabaseBig Data Analytics

You can use positional operator $ for this. Let us first create a collection with documents −

> db.subElementQueryingDemo.insertOne(
...    {
...       "ClientName":"Chris",
...       "Status": [ { "isMarried": true }, { "isMarried": false } ]
...    }
... );
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5ccf28c9dceb9a92e6aa1953")
}

Following is the query to display all documents from a collection with the help of find() method −

> db.subElementQueryingDemo.find().pretty();

This will produce the following output −

{
   "_id" : ObjectId("5ccf28c9dceb9a92e6aa1953"),
   "ClientName" : "Chris",
   "Status" : [
      {
         "isMarried" : true
      },
      {
         "isMarried" : false
      }
   ]
}

Here is how you can query sublement in MongoDB −

> db.subElementQueryingDemo.find({ "Status.isMarried": true }, {ClientName: 1, 'Status.$': 1}).pretty();

This will produce the following output −

{
   "_id" : ObjectId("5ccf28c9dceb9a92e6aa1953"),
   "ClientName" : "Chris",
   "Status" : [
      {
         "isMarried" : true
      }
   ]
}
raja
Published on 22-May-2019 11:14:33
Advertisements