For such conversion, use aggregate. Let us create a collection with documents −> db.demo343.insertOne({ ...    _id: 101, ...    UserName: "Chris", ...    details: [ ...       {"Name":"John"}, ...       {"Name":"David"} ...    ] ... } ... ); { "acknowledged" : true, "insertedId" : 101 }Display all documents from a collection with the help of find() method −> db.demo343.find().pretty();This will produce the following output −{    "_id" : 101,    "UserName" : "Chris",    "details" : [       {          "Name" : "John"       },       ... Read More

To get only specific fields in nested array documents, use $filter along with $project. Let us create a collection with documents −> db.demo342.insertOne({ ...    "Id": "101", ...       "details1" : { ...          "details2" : [ ...             { ...                "details3" : [ ...                   { ...                      "Name": "Mike", ...                      "CountryName" : "US" ... ... Read More

To find value in an array within a range, use $gt and $lt. Let us create a collection with documents −> db.demo341.insertOne({ ...    "Name": "Chris", ...       "productDetails" : [ ...          { ...             "ProductPrice" : { ...             "Price" : 800 ...          } ...       }, ...       { ...          "ProductPrice" : { ...             "Price" : 400 ...          } ... ... Read More

To get only a single result, use findOne() and fetch on the basis of id. Let us create a collection with documents −> db.demo340.insertOne({_id:1, "Name":"Chris", Age:21}); { "acknowledged" : true, "insertedId" : 1 } > db.demo340.insertOne({_id:2, "Name":"David", Age:23}); { "acknowledged" : true, "insertedId" : 2 } > db.demo340.insertOne({_id:3, "Name":"Bob", Age:20}); { "acknowledged" : true, "insertedId" : 3 } > db.demo340.insertOne({_id:4, "Name":"Sam", Age:19}); { "acknowledged" : true, "insertedId" : 4 }Display all documents from a collection with the help of find() method −> db.demo340.find();This will produce the following output −{ "_id" : 1, "Name" : "Chris", "Age" : 21 } { ... Read More

For this, use aggregate along with $zip. The zip is used to transpose an array. Let us create a collection with documents −> db.demo339.insertOne({Id:101, Score1:["98", "56"], Score2:[67, 89]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e529ee5f8647eb59e5620a2") }Display all documents from a collection with the help of find() method −> db.demo339.find();This will produce the following output −{ "_id" : ObjectId("5e529ee5f8647eb59e5620a2"), "Id" : 101, "Score1" : [ "98", "56" ], "Score2" : [ 67, 89 ] }Following is the query to zip two arrays with $zip and create a new array of object −> db.demo339.aggregate([ ...    { ...     ... Read More

The $concatArrays is used to concatenate arrays to return the concatenated array.Let us create a collection with documents −> db.demo338.insertOne({"Name":"Chris", "Marks1":[ [56, 67, 45], [67, 89, 90, 91]]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e5299baf8647eb59e56209f") }Display all documents from a collection with the help of find() method −> db.demo338.find().pretty();This will produce the following output −{    "_id" : ObjectId("5e5299baf8647eb59e56209f"),    "Name" : "Chris",    "Marks1" : [       [          56,          67,          45       ],       [         ... Read More

To get the sum, use $sum along with aggregate(). Let us create a collection with documents −> db.demo337.insertOne({"Amount":100}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e5231e5f8647eb59e56209b") } > db.demo337.insertOne({"Amount":500}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e5231e9f8647eb59e56209c") } > db.demo337.insertOne({"Amount":400}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e5231ebf8647eb59e56209d") }Display all documents from a collection with the help of find() method −> db.demo337.find();This will produce the following output −{ "_id" : ObjectId("5e5231e5f8647eb59e56209b"), "Amount" : 100 } { "_id" : ObjectId("5e5231e9f8647eb59e56209c"), "Amount" : 500 } { "_id" : ObjectId("5e5231ebf8647eb59e56209d"), "Amount" : 400 }Following is the query to calculate sum ... Read More

To update only one property, use $addToSet in MongoDB. Let us create a collection with documents −> db.demo336.insertOne({"Name":"Chris", "Score":[45, 67, 78]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e522cb1f8647eb59e562097") } > db.demo336.insertOne({"Name":"David", "Score":[89, 93, 47]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e522cb2f8647eb59e562098") }Display all documents from a collection with the help of find() method −> db.demo336.find();This will produce the following output −{ "_id" : ObjectId("5e522cb1f8647eb59e562097"), "Name" : "Chris", "Score" : [ 45, 67, 78 ] } { "_id" : ObjectId("5e522cb2f8647eb59e562098"), "Name" : "David", "Score" : [ 89, 93, 47 ] }Following is the query to update only ... Read More

For such conversion, use aggregate(). Let us create a collection with documents −> db.demo335.insertOne({"Value":"45, 67, 78.0"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e522a1cf8647eb59e562091") } > db.demo335.insertOne({"Value":"17664, 76, 534.0"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e522a26f8647eb59e562092") } > db.demo335.insertOne({"Value":"8899, 322, 135, 875.50"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e522a34f8647eb59e562093") } > db.demo335.insertOne({"Value":"1, 533.07"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e522ab9f8647eb59e562094") }Display all documents from a collection with the help of find() method −> db.demo335.find();This will produce the following output −{ "_id" : ObjectId("5e522a1cf8647eb59e562091"), "Value" : "45, 67, 78.0" } { "_id" : ObjectId("5e522a26f8647eb59e562092"), ... Read More

For this, use aggregate() in MongoDB. Let us create a collection with documents −> db.demo334.insertOne({ ...    "Name": "Chris", ...    "Age": 21, ...    "details": [{ ...       "Subject": "MySQL", ...       "Score": 78 ...    }, { ...       "Subject": "MongoDB", ...       "Score": 45 ...    }] ... } ... ); {    "acknowledged" : true,    "insertedId" : ObjectId("5e52241bf8647eb59e562090") }Display all documents from a collection with the help of find() method −> db.demo334.find().pretty();This will produce the following output −{    "_id" : ObjectId("5e52241bf8647eb59e562090"),    "Name" : "Chris",   ... Read More