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To get a list of values, use $group aggregation along with $push operator. Let us first create a collection with documents −> db.groupByDemo.insertOne({"UserName":"John", "Subject":"MongoDB"}); { "acknowledged" : true, "insertedId" : ObjectId("5cd69f0457806ebf1256f136") } > db.groupByDemo.insertOne({"UserName":"Larry", "Subject":"MySQL"}); { "acknowledged" : true, "insertedId" : ObjectId("5cd69f0657806ebf1256f137") } > db.groupByDemo.insertOne({"UserName":"John", "Subject":"Java"}); { "acknowledged" : true, "insertedId" : ObjectId("5cd69f0d57806ebf1256f138") } > db.groupByDemo.insertOne({"UserName":"John", "Subject":"C"}); { "acknowledged" : true, "insertedId" : ObjectId("5cd69f1357806ebf1256f139") } > db.groupByDemo.insertOne({"UserName":"Larry", "Subject":"SQL Server"}); { "acknowledged" : true, "insertedId" : ObjectId("5cd69f1c57806ebf1256f13a") }Following is the query to display all documents from a collection with the help ... Read More
The placeholder attribute of the element is used to set a hint for the input that would give a short description about what is expected in that particular input. This attribute works for the following input types − text, url, search, email, password and tel. It introduced in HTML5.Following is the syntax −Here, placeholder_text is the short hint i.e. placeholder which would be visible to the users whenever they will visit that web page.Let us now see an example to implement the placeholder attribute of the element −Example Live Demo Register Id − ... Read More
Scroll View is one of the most difficult and complicated topic an iOS Developer come across. Here we will be seeing how to disable Scroll View Programmatically.For disabling the same we need to make the “isScrollEnabled” property of our scroll view to false.Copy the below code in your file.import UIKit class ViewController: UIViewController { @IBOutlet var scrollView: UIScrollView! override func viewDidLoad() { super.viewDidLoad() scrollView.isScrollEnabled = false } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. } }
Let us first create a table −mysql> create table DemoTable -> ( -> NumberOfItems int, -> Amount int -> ); Query OK, 0 rows affected (0.57 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(4, 902); Query OK, 1 row affected (0.45 sec) mysql> insert into DemoTable values(5, 1000); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(3, 80); Query OK, 1 row affected (0.12 sec)Display all records from the table using select statement −mysql> select *from DemoTable;Output+---------------+--------+ | NumberOfItems | Amount | +---------------+--------+ | ... Read More
Here we will see how we can get the number of common divisors of two numbers. We are not going to find all common divisors, but we will count how many common divisors are there. If two numbers are like 12 and 24, then common divisors are 1, 2, 3, 4, 6, 12. So there are 6 common divisors, so the answer will be 6.AlgorithmcountCommonDivisor(a, b)begin count := 0 gcd := gcd of a and b for i := 1 to square root of gcd, do if gcd is divisible by 0, then ... Read More
The following is an example to display the first element in a JComboBox in Java:Exampleimport java.awt.BorderLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextArea; public class SwingDemo { public static void main(String[] args) { JPanel panel = new JPanel(new BorderLayout()); String[] strArr = new String[] { "Laptop", "Mobile", "Desktop", "Tablet" }; JComboBox comboBox = new JComboBox(strArr); panel.add(comboBox, BorderLayout.NORTH); JTextArea text = new JTextArea(5, 5); panel.add(text, BorderLayout.CENTER); JButton btn = new JButton("Click"); ... Read More
The SQL UNION clause/operator is used to combine the results of two or more SELECT statements without returning any duplicate rows.To use this UNION clause, each SELECT statement must haveThe same number of columns selectedThe same number of column expressionsThe same data type andHave them in the same orderBut they need not have to be in the same length.The basic syntax of a UNION clause is as follows −SyntaxSELECT column1 [, column2 ] FROM table1 [, table2 ] [WHERE condition] UNION SELECT column1 [, column2 ] FROM table1 [, table2 ] [WHERE condition]The supportsUnion() method of the DatabaseMetaData interface is used to ... Read More
Odd number summation using JavaScript. Live DemoExample var tot = 0; var a = [1,45,78,9,78,40,67,76]; for(var i = 0; i
Let’s say we have a menu and within that we need to set the JRadioButtonMenuItem. Here’s the Menu −JMenu editMenu = new JMenu("Edit"); editMenu.setMnemonic(KeyEvent.VK_E); menuBar.add(editMenu);Now, set the editMenu and add it to the MenuBar −JMenu editMenu = new JMenu("Edit"); editMenu.setMnemonic(KeyEvent.VK_E); menuBar.add(editMenu);Now, create Options Menu and add it to the editMenu −JMenu optionsMenu = new JMenu("Options"); optionsMenu.setMnemonic(KeyEvent.VK_O); editMenu.add(optionsMenu);Now, set the JRadioButtonMenuItem and add it to the editMenu created above −ButtonGroup group = new ButtonGroup(); JRadioButtonMenuItem radioMenuItem = new JRadioButtonMenuItem("SmartInsertMode", true); radioMenuItem.setMnemonic(KeyEvent.VK_I); optionsMenu.add(radioMenuItem); group.add(radioMenuItem); JRadioButtonMenuItem radioMenuItem2 = new JRadioButtonMenuItem("SmartDeleteMode"); radioMenuItem.setMnemonic(KeyEvent.VK_D); optionsMenu.add(radioMenuItem2); group.add(radioMenuItem2);The following is an example add JRadioButtonMenuItem in Java −Examplepackage my; ... Read More
For this, use the ORDER BY clause. Let us first create a table −mysql> create table DemoTable ( StudentId int ); Query OK, 0 rows affected (0.59 sec)Now you can insert some records in the table using insert command −mysql> insert into DemoTable values(100); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(60); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(70); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(45); Query OK, 1 row affected (0.24 sec) mysql> insert into DemoTable values(55); Query OK, 1 row affected ... Read More