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You can use getSiblingDB() from MongoDB for this using var keyword from JS −anyVariableName= db.getSiblingDB(‘yourDatabaseName’);Let us implement the above syntax in order to select database −> selectedDatabase = db.getSiblingDB('sample');This will produce the following output −SampleNow, insert some documents. Let’s say the collection is ‘selectDatabaseDemo’ −> db.selectDatabaseDemo.insertOne({"ClientName":"John Smith", "ClientAge":23}); { "acknowledged" : true, "insertedId" : ObjectId("5cda794b5667f1cce01d55ad") } > db.selectDatabaseDemo.insertOne({"ClientName":"Carol Taylor", "ClientAge":24}); { "acknowledged" : true, "insertedId" : ObjectId("5cda79565667f1cce01d55ae") }Display all documents from a collection with the help of find() method −db.selectDatabaseDemo.find().pretty();This will produce the following output −{ "_id" : ObjectId("5cda794b5667f1cce01d55ad"), "ClientName" : "John Smith", ... Read More
Create a check box first and set valueJCheckBox checkBox = new JCheckBox("In-Stock");Set the JCheckBox for the editor so that the editor uses the check box −TreeCellEditor editor = new DefaultCellEditor(comboBox); tree.setEditable(true); tree.setCellEditor(editor);The following is an example to create a Default Cell Editor that uses a JCheckBox −Examplepackage my; import javax.swing.DefaultCellEditor; import javax.swing.JCheckBox; import javax.swing.JFrame; import javax.swing.JTree; import javax.swing.tree.DefaultMutableTreeNode; import javax.swing.tree.TreeCellEditor; public class SwingDemo { public static void main(String[] args) throws Exception { JFrame frame = new JFrame("Demo"); DefaultMutableTreeNode node = new DefaultMutableTreeNode("Products"); DefaultMutableTreeNode node1 = new DefaultMutableTreeNode("Clothing"); ... Read More
To create a confirmation dialog box in Java, use the Java Swing JOptionPane.showConfirmDialog() method, which allows you to create a dialog box that asks for confirmation from the user. For example, Do you want to restart the system?, “This file contains a virus, Do you want to still download?”, etc. Kt comes with a type JOptionPane.YES_NO_CANCEL_OPTION for the same confirmation.The following is an example to create a Confirmation Dialog Box in Java −Examplepackage my; import java.awt.Dimension; import javax.swing.ImageIcon; import javax.swing.JLabel; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.SwingConstants; import javax.swing.UIManager; public class SwingDemo { public static void main(String[] args) { ... Read More
The query SELECT NOW() gives the current date as well as current time. If you want only current date, use only CURDATE(). Following is the syntax for datetime −SELECT NOW();The syntax for only date.SELECT CURDATE();Let us now implement the above syntax −Case 1 : If you want both current date and time −mysql> SELECT NOW();Output+-----------------------+ | NOW() | +-----------------------+ | 2019-06-02 15 :30 :39 | +-----------------------+ 1 row in set (0.00 sec)Case 2 : If you want the current date only −mysql> SELECT CURDATE();Output+------------+ | CURDATE() | +------------+ | 2019-06-02 | +------------+ 1 row in set (0.00 sec)
Binary search is a fast search algorithm with run-time complexity of Ο(log n). This search algorithm works on the principle of divide and conquer. For this algorithm to work properly, the data collection should be in the sorted form.Binary search looks for a particular item by comparing the middle most item of the collection. If a match occurs, then the index of item is returned. If the middle item is greater than the item, then the item is searched in the sub-array to the left of the middle item. Otherwise, the item is searched for in the sub-array to the ... Read More
To compile a program, you doesn’t really need a main method in your program. But, while execution JVM searches for the main method. In the Java the main method is the entry point Whenever you execute a program in Java JVM searches for the main method and starts executing from it.The main method must be public, static, with return type void, and a String array as argument.public static int main(String[] args){ }You can write a program without defining a main it gets compiled without compilation errors. But when you execute it a run time error is generated saying “Main method ... Read More
The HTML DOM Input Checkbox form property returns the form containing the input checkbox.SyntaxFollowing is the syntax −Returning reference to the form objectinputCheckboxObject.formExampleLet us see an example of HTML DOM Input Checkbox form property − Live Demo Student Details Show Form ID: Get ID of form containing this Checkbox function getFormID(){ var checkboxFilter = document.getElementById("formID"); var showResultDiv = document.getElementById("showResult"); if(checkboxFilter.checked == true){ showResultDiv.textContent = 'Form ID: ' + checkboxFilter.form.id; } else { showResultDiv.textContent = 'Check the checkbox'; } } OutputThis will produce the following output −Before checking ‘Show Form ID’ checkbox −After checking ‘Show Form ID’ checkbox −
The Breadth First Search (BFS) traversal is an algorithm, which is used to visit all of the nodes of a given graph. In this traversal algorithm one node is selected and then all of the adjacent nodes are visited one by one. After completing all of the adjacent vertices, it moves further to check another vertices and checks its adjacent vertices again.In The competitive coding, we have to solve problems very quickly. We will use the STL (Standard Library of C++) to implement this algorithm, we need to use the Queue data structure. All the adjacent vertices are added into ... Read More
Let us create a list first with string elements. Some of the elements are null in the List:List list = Arrays.asList("Jack", null, "Thor", null, "Loki", "Peter", null, "Hulk");Now, sort the above list and place nulls first with nullsFirst:list.sort(Comparator.nullsFirst(String::compareTo));The following is an example to sort a List that places nulls first:Exampleimport java.util.Arrays; import java.util.Comparator; import java.util.List; public class Demo { public static void main(String... args) { List list = Arrays.asList("Jack", null, "Thor", null, "Loki", "Peter", null, "Hulk"); System.out.println("Initial List = "+list); list.sort(Comparator.nullsFirst(String::compareTo)); System.out.println("List placing nulls first = "+list); ... Read More
The CTRL + C is used to send an interrupt to the current executing task. In this program, we will see how to catch the CTRL + C event using C++.The CTRL + C is one signal in C or C++. So we can catch by signal catching technique. For this signal, the code is SIGINT (Signal for Interrupt). Here the signal is caught by signal() function. Then one callback address is passed to call function after getting the signal.Please see the program to get the better idea.Example#include #include #include #include using namespace std; // Define ... Read More