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Articles on Trending Technologies
Technical articles with clear explanations and examples
How to group nested fields in MongoDB aggregation with count value in array?
At first, let us create a collection with documents −> db.demo99.insertOne( ... { ... ... 'Details': ... { ... 'X': ... { ... 'Values': [10, 30, 50], ... 'Number':3, ... }, ... 'Y': ... { ... 'Values': [1000, 180], ... 'Number': 2, ... } ... } ...
Read MoreIncrement a property value of an element in array object with MongoDB
To increment a property value of an element, use update() in MongoDB and in that, work with #$inc to increment. Let us first create a collection with documents −> db.demo97.insertOne({ ... "Details": [ ... { ... "Name": "Chris", ... "Marks": 45 ... }, ... { ... "Name": "Bob", ... "Marks": 88 ... }y ... ] ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5e2d6d24b8903cdd865577af") }Display all ...
Read MoreFind sum of fields inside array in MongoDB?
To find sum of fields inside array, use $sum. Let us create a collection with documents −> db.demo96.insertOne( ... { ... ... "Name" : "Chris", ... "Details" : [ ... { ... Marks:67 ... }, ... { ... Marks:33 ... }, ... { ... Marks:50 ... } ... ] ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5e2d6aadb8903cdd865577ad") }Display all documents from a ...
Read MoreHow to update array with multiple conditions in MongoDB
To update array with multiple conditions, use $push in MongoDB. Let us create a collection with documents −> db.demo94.insertOne( ... { ... ... "Details" : [ ... { ... "Name" : "Chris", ... "Subject" : [] ... }, ... { ... "Name" : "David", ... "Subject" : [] ... }, ... { ... "Name" : "Bob", ... "Subject" : [] ...
Read MoreHow to convert date to timestamp in MongoDB
To convert date to timestamp in MongoDB, use aggregate(). Let us create a collection with documents −> db.demo93.insertOne({"UserName":"Chris", "ArrivalDate":new ISODate("2020-10-01")}); { "acknowledged" : true, "insertedId" : ObjectId("5e2d4b6479799acab037af68") } > db.demo93.insertOne({"UserName":"David", "ArrivalDate":new ISODate("2019-12-31")}); { "acknowledged" : true, "insertedId" : ObjectId("5e2d4b7379799acab037af69") }Display all documents from a collection with the help of find() method −> db.demo93.find();This will produce the following output −{ "_id" : ObjectId("5e2d4b6479799acab037af68"), "UserName" : "Chris", "ArrivalDate" : ISODate("2020-10-01T00:00:00Z") } { "_id" : ObjectId("5e2d4b7379799acab037af69"), "UserName" : "David", "ArrivalDate" : ISODate("2019-12-31T00:00:00Z") }Following is the query to convert date to timestamp in MongoDB −> db.demo93.aggregate([ ... { "$match": ...
Read MoreFind records on or after a specific date in MongoDB?
To find records on or after a date, use $gte i.e., greater than equal. Let us create a collection with documents −> db.demo91.insertOne({"ArrivalDate":new ISODate("2020-01-10")}); { "acknowledged" : true, "insertedId" : ObjectId("5e2d49fd79799acab037af66") } > db.demo91.insertOne({"ArrivalDate":new ISODate("2019-12-14")}); { "acknowledged" : true, "insertedId" : ObjectId("5e2d4a0679799acab037af67") }Display all documents from a collection with the help of find() method −> db.demo91.find();This will produce the following output −{ "_id" : ObjectId("5e2d49fd79799acab037af66"), "ArrivalDate" : ISODate("2020-01-10T00:00:00Z") } { "_id" : ObjectId("5e2d4a0679799acab037af67"), "ArrivalDate" : ISODate("2019-12-14T00:00:00Z") }Following is the query to find records on or after a specific date in MongoDB −> db.demo91.find({ArrivalDate: { $gte: ISODate('2020-01-10') ...
Read MoreMongoDB query to find documents whose array contains a string that is a substring of a specific word
For such evaluations, use aggregate() in MongoDB. Let us create a collection with documents −> db.demo90.insertOne( ... {"words": ["john", "jace"] ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5e2c1ada79799acab037af56") } > db.demo90.insertOne( ... {"words": ["sam", "adam"] ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5e2c1adb79799acab037af57") }Display all documents from a collection with the help of find() method −> db.demo90.find();This will produce the following output −{ "_id" : ObjectId("5e2c1ada79799acab037af56"), "words" : [ "john", "jace" ] } { "_id" : ObjectId("5e2c1adb79799acab037af57"), "words" : [ "sam", "adam" ] }Following is the query to find documents ...
Read MoreMongoDB query to get array of nested string?
To get array of nested string in MongoDB, use dot notation in find(). Let us create a collection with documents −> db.demo89.insertOne( ... { id: 101, Details: [ { Name: "Chris", Marks: 45 }, { Name: "David", Marks: 55, Subjects : ["MySQL", "MongoDB", "Java", "C"] } ] ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5e2c163b79799acab037af51") } > db.demo89.insertOne( ... { id: 102, Details: [ { Name: "Mike", Marks: 48 }, { Name: "Bob", Marks: 98, Subjects : ["C++", "MySQL"] } ] ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5e2c163c79799acab037af52") }Display ...
Read MoreIs it possible to use MongoDB field value as a pattern in $regex?
Yes, you can use $indexOfCP to use a filed value as a pattern. Let us create a collection with documents −> db.demo88.insertOne( ... { ... "Name": "Chris", ... "PassoutYear": "2020", ... "websiteName": "chris.shop.com/Carol-2020-" ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5e2c14c471bf0181ecc422b1") } > db.demo88.insertOne( ... { ... "Name": "David", ... "PassoutYear": "2010", ... "websiteName": "david.bigshop.com/David-2010-" ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5e2c14c571bf0181ecc422b2") }Display all documents from a ...
Read MoreMongoDB query to exclude if id is equal to a document field array value
For this, use $not along with $in. Let us create a collection with documents −[ { id: "101", subjectid: [ "102" ] }, { id: "102", subjectid: [ "102" ] } ]Here is the snapshot.Display all documents from a collection with the help of find() method −db.collection.find()This will produce the following output −[ { "_id": ObjectId("5a934e000102030405000000"), "id": "101", "subjectid": [ "102" ] }, { "_id": ObjectId("5a934e000102030405000001"), "id": "102", "subjectid": [ "102" ] } ]Following is the query that uses $expr, $not and $in to fetch values excluding matching field array value −db.collection.find({ $expr: { $not:{ $in: [ "$id", "$subjectid" ] } } })This will produce the following output −[ { "_id": ObjectId("5a934e000102030405000000"), "id": "101", "subjectid": [ "102" ] } ]
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