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You need to use custom logic with the help of while loop along with find() cursor. Let us create a collection with documents −> db.demo724.insertOne( ... { ... details: ... { ... id:101, ... otherDetails:[ ... {Name:"Chris"} ... ] ... } ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5eab0cce43417811278f5890") } > > > db.demo724.insertOne( ... { ... ... } ... ); { "acknowledged" : true, ... Read More
We are given the two numbers let’s say x and y and the task is to find the common prime factors between two numbers. Common prime factors can be found by firstly calculating the common numbers between two numbers and after that checking from the list of common factors the one which are prime numbers.For ExampleInput − x = 10 y = 20 Output − Common prime factor of two numbers are: 2 5Explanation − common primes factors between 10 and 20 are 2 and 5 only.Input − x = 34 y = 12 Output − Common prime factor of ... Read More
To count array elements from a specific field, use $size in MongoDB. Let us create a collection with documents −> db.demo723.insertOne({"Subject":["MySQL", "MongoDB"]}); { "acknowledged" : true, "insertedId" : ObjectId("5eab094d43417811278f588a") } > db.demo723.insertOne({"Subject":["C"]}); { "acknowledged" : true, "insertedId" : ObjectId("5eab095243417811278f588b") } > db.demo723.insertOne({"Subject":["C++", "Java", "Python"]}); { "acknowledged" : true, "insertedId" : ObjectId("5eab095f43417811278f588c") }Display all documents from a collection with the help of find() method −> db.demo723.find();This will produce the following output −{ "_id" : ObjectId("5eab094d43417811278f588a"), "Subject" : [ "MySQL", "MongoDB" ] } { "_id" : ObjectId("5eab095243417811278f588b"), "Subject" : [ "C" ] } { "_id" : ... Read More
To ignore null values in MongoDB, use "$ne" : null in aggregate(). Let us create a collection with documents −> db.demo722.insertOne( ... { ... id:101, ... details: [ ... { Name:""}, ... { Name: "David"}, ... {Name:null}, ... {Name:"Carol"} ... ] ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5eab07d543417811278f5889") }Display all documents from a collection with the help of find() method −> db.demo722.find();This will produce the following output ... Read More
We are given the range having start and end numbers and the task is to calculate the total count of Fibonacci numbers available between the given range in O(Log n) time and O(1) space.What are Fibonacci numbersFibonacci numbers are the sequence of numbers known as Fibonacci sequence where every new number is the sum of the last two preceding numbers.Where, f(0) = 0 and f(1) = 1 i.e. f(0) and f(1) have fixed positions in the sequence and the calculation will start from the third number.Formula used for calculating the sequence is −Fn = Fn-1 + Fn-2Where, F0 = 0, ... Read More
To count by multiple fields, use $facet in MongoDB. The $facet processes multiple aggregation pipelines within a single stage on the same set of input documents. Let us create a collection with documents −> db.demo721.insertOne( ... { ... ... "details1": { ... "id":101 ... ... }, ... "details2": { ... "id":101 ... }, ... "details3": { ... "id":101 ... } ... } ... ); { "acknowledged" : ... Read More
To update all the values, use update() along with multi:true. Let us create a collection with documents −> db.demo720.insertOne({"SubjectName":"MySQL"}); { "acknowledged" : true, "insertedId" : ObjectId("5eaae7ca43417811278f5883") } > db.demo720.insertOne({"SubjectName":"Java"}); { "acknowledged" : true, "insertedId" : ObjectId("5eaae7ce43417811278f5884") } > db.demo720.insertOne({"SubjectName":"C"}); { "acknowledged" : true, "insertedId" : ObjectId("5eaae7d143417811278f5885") } > db.demo720.insertOne({"SubjectName":"C++"}); { "acknowledged" : true, "insertedId" : ObjectId("5eaae7d543417811278f5886") }Display all documents from a collection with the help of find() method −> db.demo720.find();This will produce the following output −{ "_id" : ObjectId("5eaae7ca43417811278f5883"), "SubjectName" : "MySQL" } { "_id" : ObjectId("5eaae7ce43417811278f5884"), "SubjectName" : "Java" } { ... Read More
To add a new field, use the $addFields in MongoDB. Let us create a collection with documents −> db.demo719.insertOne( ... { ... "Number":"7374644", ... "details" : { ... "otherDetails" : [ ... { ... "ProductId" :"102", ... "ProductPrice" : NumberInt(500) ... }, ... { ... "ProductId" :"103", ... ... Read More
We are given an integer value and the task is to first calculate the factorial of a number and then calculate the total number of digits in a result.What is a factorial numberFactorial of a number is calculated by multiplying the digits in a number while decrementing the value of digit by 1. It is denoted by the symbol ‘!’ i.e. 0!, 1!, 2!, 3!, 5!, ...., etc. Factorial of 0! and 1! is always 1.I.e. factorial of 2 = 2 * (2-1) = 2 * 1 = 2 factorial of 3 = 3 * (3-1) * ... Read More
We are given the range starting from an integer value holded by a variable let’s say start till the variable end and the task is to count the total number of factorial numbers available in the given range.What is a factorial numberFactorial of a number is calculated by multiplying the digits in a number while decrementing thevalue of digit by 1. It is denoted by the symbol ‘!’ i.e. 0!, 1!, 2!, 3!, 5!, ...., etc. Factorial of 0! and 1! is always 1.I.e. factorial of 2 = 2 * (2-1) = 2 * 1 = 2 ... Read More