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To get MongoDB databases in a JavaScript array, you can use runCommand(). Following is the query to get MongoDB databases in a JavaScript array> use admin; switched to db admin > allDatabasesDetails = db.runCommand({listDatabases: 1});This will produce the following output{ "databases" : [ { "name" : "admin", "sizeOnDisk" : 847872, "empty" : false }, { "name" : "config", "sizeOnDisk" : 98304, "empty" : false ... Read More
Use the concept of IFNULL() method to treat NULL as 0. Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Value1 int, Value2 int ); Query OK, 0 rows affected (0.64 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Value1, Value2) values(10, 20); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(Value1, Value2) values(null, null); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(Value1, Value2) values(40, null); Query OK, 1 row affected (0.18 sec)Following is the query to display all ... Read More
A view of the ByteBuffer can be created as a FloatBuffer using the asFloatBuffer() method in the class java.nio.ByteBuffer. This method requires no parameters and it returns a float buffer as required. This buffer reflects the changes made to the original buffer and vice versa.A program that demonstrates this is given as follows −Example Live Demoimport java.nio.*; import java.util.*; public class Demo { public static void main(String[] args) { int n = 50; try { ByteBuffer bufferB = ByteBuffer.allocate(n); FloatBuffer bufferF = bufferB.asFloatBuffer(); ... Read More
In this program we take a matrix and prints the transpose of the matrix. In a transpose matrix, rows become columns and vice versa.AlgorithmBegin Take number of rows and columns of the matrix. Take The elements of the matrix and stored in the matrix ‘A’. The transpose matrix is found by exchanging the rows with columns and columns with rows. Print both the original matrix and the transpose. End.Example Code#include using namespace std; int main () { int A[10][10], a, b, i, j; cout > a>> b; cout > A[i][j]; cout
Yes, you can use regexp to make a case-insensitive query in MongoDB. The syntax is as follows:db.yourCollectionName.find({"yourFieldName":/^yourvalue$/i});To understand the above syntax, let us create a collection with some documents. The query to create a collection with documents is as follows:> db.caseInsensitiveDemo.insertOne({"Name":"John"}); { "acknowledged" : true, "insertedId" : ObjectId("5c6d7a67f2db199c1278e7ef") } > db.caseInsensitiveDemo.insertOne({"Name":"JOHN"}); { "acknowledged" : true, "insertedId" : ObjectId("5c6d7ad6f2db199c1278e7f0") }Display all documents from a collection with the help of find(). The query is as follows:> db.caseInsensitiveDemo.find();The following is the output:{ "_id" : ObjectId("5c6d7a67f2db199c1278e7ef"), "Name" : "John" } { "_id" : ObjectId("5c6d7ad6f2db199c1278e7f0"), "Name" : "JOHN" }Here is the ... Read More
Following is the while loop example − WHILE LOOP Example JSP Tutorial The above code will generate the following result −JSP Tutorial JSP Tutorial JSP Tutorial
The DoubleStream class in Java the following two forms of the of() methodThe following of() method returns a sequential DoubleStream containing a single element. Here is the syntaxstatic DoubleStream of(double t)Here, parameter t is the single element.The following of() method returns a sequential ordered stream whose elements are the specified valuesstatic DoubleStream of(double… values)Here, the parameter values are the elements of the new stream.To use the DoubleStream class in Java, import the following packageimport java.util.stream.DoubleStream;The following is an example to implement DoubleStream of() method in JavaExample Live Demoimport java.util.stream.DoubleStream; public class Demo { public static void main(String[] args) ... Read More
The month name for a particular LocalDate can be obtained using the getMonth() method in the LocalDate class in Java. This method requires no parameters and it returns the month name in the year.A program that demonstrates this is given as followsExample Live Demoimport java.time.*; public class Demo { public static void main(String[] args) { LocalDate ld = LocalDate.parse("2019-02-14"); System.out.println("The LocalDate is: " + ld); System.out.println("The month is: " + ld.getMonth()); } }OutputThe LocalDate is: 2019-02-14 The month is: FEBRUARYNow let us understand the above program.First the LocalDate is displayed. ... Read More
Data hiding is one of the important features of Object Oriented Programming which allows preventing the functions of a program to access directly the internal representation of a class type. The access restriction to the class members is specified by the labeled access modifiers: public, private, and protected sections within the class body.The default access for members and classes is private.Example Codeclass Base { public: // public members go here protected: // protected members go here private: ... Read More
There is no in-built function to count a number of keys in a document. In order to count a number of keys, you need to write some code.Let us create a collection with a document. The query to create a collection with a document is as follows −> db.numberofKeysInADocumentDemo.insertOne({ "UserName":"John", "UserAge":21, "UserEmailId":"john12@gmail.com", "UserCountryName":"US"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9132584afe5c1d2279d6ac") }Display all documents from a collection with the help of find() method. The query is as follows −> db.numberofKeysInADocumentDemo.find().pretty();The following is the output −{ "_id" : ObjectId("5c9132584afe5c1d2279d6ac"), "UserName" : "John", "UserAge" : 21, ... Read More