Use $mod to get the even numbers and pull them from the array. Let us first create a collection with documents −>db.pullEvenNumbersDemo.insertOne({"AllNumbers":[101, 102, 104, 106, 108, 109, 110, 112, 14, 17, 18, 21]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd45b072cba06f46efe9eea") }Following is the query to display all documents from the collection with the help of find() method −> db.pullEvenNumbersDemo.find().pretty();This will produce the following output −{    "AllNumbers" : [       102,       104,       106,       108,       109,       110,       112,   ... Read More

You can use update() along with $ operator for this. Let us first create a collection with documents −> db.addAFieldDemo.insertOne( ...   { ... ...      "ClientName" : "Larry", ...      "ClientCountryName" : "US", ...      "ClientOtherDetails" : [ ...         { ...            "ClientProjectName":"Online Banking System" ...         } ...      ] ...   } ... ); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd44bdc2cba06f46efe9ee8") }Following is the query to display all documents from a collection with the help of find() method −>  db.addAFieldDemo.find().pretty();This ... Read More

You can use $avg operator along with aggregate framework. Let us first create a collection with documents −> db.averageOfRatingsInArrayDemo.insertOne( ...   { ...      "StudentDetails":[ ...         { ...             "StudentId":1, ...             "StudentScore":45 ...         }, ...         { ...           "StudentId":2, ...           "StudentScore":58 ...         }, ...         { ...           "StudentId":3, ...     ... Read More

You can use $or operator along with limit(1) to match element in array. Let us first create a collection with documents −> db.matchElementInArrayDemo.insertOne( ...   { ...      "StudentName" : "Chris" , ...      "StudentOtherDetails" : ...      [ ...         {"StudentCountryName" : "US" , "StudentSkills" : "MongoDB"}, ...         {"StudentCountryName" : "UK" , "StudentSkills" : "Java"} ...       ] ...   } ... ); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd423282cba06f46efe9ee2") } > db.matchElementInArrayDemo.insertOne( ...   { ...      "StudentName" : "Chris" , ...   ... Read More

To get specific object from array of objects, use positional operator($). Let us first create a collection with documents −> db.getASpecificObjectDemo.insertOne( ...   { ...      _id :1, f ...      "CustomerName" : "Larry", ...      "CustomerDetails" : { ...         "CustomerPurchaseDescription": [{ ...            id :100, ...            "ProductName" : "Product-1", ...            "Amount":10000 ...         }, { ...               id :101, ...               "ProductName" : ... Read More

You can use aggregate framework for this. Let us first create a collection with documents −> db.summingSubDocumentDemo.insertOne( ... { "_id" :101, "CustomerDetails" : { "CustomerPurchase" : { "CustomerPurchaseAmount" : 2000 } } }); { "acknowledged" : true, "insertedId" : 101 } > db.summingSubDocumentDemo.insertOne( { "_id" :102, "CustomerDetails" : { "CustomerPurchase" : { "CustomerPurchaseAmount" : 3000 } } }); { "acknowledged" : true, "insertedId" : 102 } > db.summingSubDocumentDemo.insertOne( { "_id" :103, "CustomerDetails" : { "CustomerPurchase" : { "CustomerPurchaseAmount" : 5000 } } }); { "acknowledged" : true, "insertedId" : 103 }Following is the query to display all documents ... Read More

To retrieve multiple items in an array, use aggregate framework. Let us first create a collection with documents −> db.retrieveMultipleDemo.insertOne( ...   { ...      "UserDetails": ...      [ ...         { "_id": "101", "UserName":"John", "UserAge": 23 }, ...         { "_id": "102", "UserName":"Carol", "UserAge": 21 }, ...         { "_id": "103", "UserName":"David", "UserAge": 23}, ...         { "_id": "104", "UserName":"Sam", "UserAge": 25} ...      ] ...   } ... ); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd40c85edc6604c74817cf0") }Following is the query to ... Read More

You can use aggregate framework for this. Here, we will get the sum and then match it to search for documents less than a particular number. Let us first create a collection with documents −> db.searchDocumentsDemo.insertOne({"Value1":100, "Value2":560}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd3fe1eedc6604c74817ce9") } > db.searchDocumentsDemo.insertOne({"Value1":300, "Value2":150}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd3fe29edc6604c74817cea") } > db.searchDocumentsDemo.insertOne({"Value1":400, "Value2":200}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd3fe30edc6604c74817ceb") } > db.searchDocumentsDemo.insertOne({"Value1":190, "Value2":210}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd3fe45edc6604c74817cec") }Following is the query to display all documents from a collection with the help of ... Read More

Let us first create a collection with documents −>db.missingDocumentDemo.insertOne({"StudentFirstName":"Adam", "StudentLastName":"Smith"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd3fb1eedc6604c74817ce6") } >db.missingDocumentDemo.insertOne({"StudentFirstName":"Carol", "StudentLastName":"Taylor"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd3fb29edc6604c74817ce7") } >db.missingDocumentDemo.insertOne({"StudentFirstName":"David", "StudentLastName":"Miller", "StudentAge":21}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd3fb40edc6604c74817ce8") }Following is the query to display all documents from a collection with the help of find() method −> db.missingDocumentDemo.find().pretty();This will produce the following output −{    "_id" : ObjectId("5cd3fb1eedc6604c74817ce6"),    "StudentFirstName" : "Adam",    "StudentLastName" : "Smith" } {    "_id" : ObjectId("5cd3fb29edc6604c74817ce7"),    "StudentFirstName" : "Carol",    "StudentLastName" : "Taylor" } {    "_id" : ... Read More

You can use $and operator for this. Let us first create a collection with documents −> db.twoSpecificIdsDemo.insertOne( ...   { ...      PlayerId:1, ...      "PlayerDetails": [{ ...         id: 100, ...         "PlayerName":"Chris" ...      }, { ...         id: 101, ...         "PlayerName":"Sam" ...      }, { ...         id: 102, ...         "PlayerName":"Robert" ...      }, { ...         id: 103, ...         "PlayerName":"Carol" ...      }] ... Read More