You can use $in operator. Let us first create a collection with documents −> db.tagCountDemo.insertOne({"ListOfNames":["John", "Sam", "Carol"]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd64b387924bb85b3f48944") } > db.tagCountDemo.insertOne({"ListOfNames":["Bob", "David", "John"]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd64b4b7924bb85b3f48945") } > db.tagCountDemo.insertOne({"ListOfNames":["Mike", "Robert", "Chris"]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd64b5d7924bb85b3f48946") } > db.tagCountDemo.insertOne({"ListOfNames":["James", "Carol", "Jace"]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd64b717924bb85b3f48947") }Following is the query to display all documents from a collection with the help of find() method −> db.tagCountDemo.find().pretty();This will produce the following output −{    "_id" : ObjectId("5cd64b387924bb85b3f48944"),    "ListOfNames" : ... Read More

To sort by sub-document match, you can use aggregate framework. Let us first create a collection with documents −> db.sortBySubDocumentsDemo.insertOne(    {       "StudentName": "Chris",       "StudentDetails": [          {             "Age":21,             "StudentScore":91          },          {             "Age":22,             "StudentScore":99          },          {             "Age":21,             "StudentScore":93   ... Read More

You can use $lte operator along with Date() for this. Let us first create a collection with documents. Here, we have set the date 2019-05-11, which is the current date −> db.getDocumentsExpiredDemo.insertOne({"ArrivalDate":new ISODate("2019-05-11")}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd563b17924bb85b3f4893b") } > db.getDocumentsExpiredDemo.insertOne({"ArrivalDate":new ISODate("2019-01-01")}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd563bf7924bb85b3f4893c") } > db.getDocumentsExpiredDemo.insertOne({"ArrivalDate":new ISODate("2019-05-10")}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd563ca7924bb85b3f4893d") } > db.getDocumentsExpiredDemo.insertOne({"ArrivalDate":new ISODate("2019-02-01")}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd563e77924bb85b3f4893e") }Following is the query to display all documents from a collection with the help of find() method −> db.getDocumentsExpiredDemo.find().pretty();This ... Read More

To update array in MongoDB document by variable index, use the below syntax. Here, yourIndexValue in the index value, where yourIndexVariableName is the variable name for index −var yourIndexVariableName= yourIndexValue, anyVariableName= { "$set": {} }; yourVariableName["$set"]["yourFieldName."+yourIndexVariableName] = "yourValue"; db.yourCollectionName.update({ "_id":  yourObjectId}, yourVariableName);Let us first create a collection with documents −> db.updateByVariableDemo.insertOne({"StudentSubjects":["MySQL", "Java", "SQL Server", "PL/SQL"]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd553c37924bb85b3f4893a") }Following is the query to display all documents from a collection with the help of find() method −> db.updateByVariableDemo.find().pretty();This will produce the following output −{    "_id" : ObjectId("5cd553c37924bb85b3f4893a"),    "StudentSubjects" : [       ... Read More

You can use map() for this. Let us first create a collection with documents −> db.deleteDemo.insertOne({"Name":"John"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd550492cba06f46efe9f06") } > db.deleteDemo.insertOne({"Name":"Carol"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd5504d2cba06f46efe9f07") } > db.deleteDemo.insertOne({"Name":"Sam"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd550512cba06f46efe9f08") } > db.deleteDemo.insertOne({"Name":"David"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd5505d2cba06f46efe9f09") } > db.deleteDemo.insertOne({"Name":"Robert"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd550682cba06f46efe9f0a") } > db.deleteDemo.insertOne({"Name":"Chris"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd5506f2cba06f46efe9f0b") } > db.deleteDemo.insertOne({"Name":"Mike"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd550752cba06f46efe9f0c") } > db.deleteDemo.insertOne({"Name":"Bob"}); ... Read More

You can use $and operator. Let us first create a collection with documents −>db.selectingASingleFieldDemo.insertOne({"StudentFirstName":"John", "StudentAge":23, "StudentCountryName":"US"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd547142cba06f46efe9f02") } >db.selectingASingleFieldDemo.insertOne({"StudentFirstName":"Carol", "StudentAge":21, "StudentCountryName":"UK"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd5471f2cba06f46efe9f03") } >db.selectingASingleFieldDemo.insertOne({"StudentFirstName":"David", "StudentAge":24, "StudentCountryName":"AUS"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd5472c2cba06f46efe9f04") } >db.selectingASingleFieldDemo.insertOne({"StudentFirstName":"Robert", "StudentAge":26, "StudentCountryName":"AUS"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd548382cba06f46efe9f05") }Following is the query to display all documents from a collection with the help of find() method −> db.selectingASingleFieldDemo.find().pretty();This will produce the following output −{    "_id" : ObjectId("5cd547142cba06f46efe9f02"),    "StudentFirstName" : "John",    "StudentAge" : ... Read More

You can use aggregate framework for this. Let us first create a collection with documents −>db.aggregationOperatorDemo.insertOne({"FirstValue":392883,"SecondValue":10000000000}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd541452cba06f46efe9f01") }Following is the query to display all documents from a collection with the help of find() method −> db.aggregationOperatorDemo.find().pretty();This will produce the following output −{    "_id" : ObjectId("5cd541452cba06f46efe9f01"),    "FirstValue" : 392883,    "SecondValue" : 10000000000 }Following is the query to use divide aggregation operator −> db.aggregationOperatorDemo.aggregate([ ...   { "$project": { "Value": { "$divide": ["$FirstValue", "$SecondValue"] } } } ... ]);This will produce the following output −{ "_id" : ObjectId("5cd541452cba06f46efe9f01"), "Value" : 0.0000392883 }

Let us first create a collection with documents −> db.searchAnArrayDemo.insertOne({_id:1, "TechnicalDetails":[{"Language":"MongoDB"}]}); { "acknowledged" : true, "insertedId" : 1 } > db.searchAnArrayDemo.insertOne({_id:2, "TechnicalDetails":[{"Language":"MySQL"}]}); { "acknowledged" : true, "insertedId" : 2 } > db.searchAnArrayDemo.insertOne({_id:3, "TechnicalDetails":[{"Language":"MongoDB"}]}); { "acknowledged" : true, "insertedId" : 3 } > db.searchAnArrayDemo.insertOne({_id:4, "TechnicalDetails":[{"Language":"MongoDB"}]}); { "acknowledged" : true, "insertedId" : 4 } > db.searchAnArrayDemo.insertOne({_id:5, "TechnicalDetails":[{"Language":"Java"}]}); { "acknowledged" : true, "insertedId" : 5 }Following is the query to display all documents from a collection with the help of find() method −> db.searchAnArrayDemo.find().pretty();This will produce the following output −{ "_id" : 1, "TechnicalDetails" : [ { "Language" : "MongoDB" } ] } ... Read More

To update the inner field, use the below syntax −db.yourCollectionName.update({"_id" : yourObjectId}, {$set : {"yourOuterFieldName.yourInnerFieldName" :yourValue}});Let us first create a collection with documents −> db.updateDocumentDemo.insertOne( ...   { ... ...      "StudentDetails" : { ...         "StudentFirstName" : "Adam", ...         "StudentLastName" : "Samith" ...      }, ...      "StudentOtherDetails" : { ...         "StudentFavouriteSubject" : "MySQL", ...         "StudentScore" : 45 ...      } ...   } ... ); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd50bb32cba06f46efe9efe") }Following is the query to ... Read More

You can use $set operator along with update(). Let us first create a collection with documents −> db.workingOfUpdateMethod.insertOne({"ClientCountryName" : "AUS"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd506fe2cba06f46efe9efa") } > db.workingOfUpdateMethod.insertOne({"ClientCountryName" : "AUS"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd507022cba06f46efe9efb") } > db.workingOfUpdateMethod.insertOne({"ClientCountryName" : "AUS"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd507022cba06f46efe9efc") } > db.workingOfUpdateMethod.insertOne({"ClientCountryName" : "AUS"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd507032cba06f46efe9efd") }Following is the query to display all documents from a collection with the help of find() method −> db.workingOfUpdateMethod.find().pretty();This will produce the following output −{ "_id" : ObjectId("5cd506fe2cba06f46efe9efa"), "ClientCountryName" ... Read More