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Articles on Trending Technologies
Technical articles with clear explanations and examples
Changing data type from date to date/time in MySQL?
To change data type from date to date/time, use alter command.alter table yourTableName change yourColumnName yourColumnName datetime;Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, LoginDate date ); Query OK, 0 rows affected (1.26 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(LoginDate) values('2019-01-21'); Query OK, 1 row affected (0.29 sec) mysql> insert into DemoTable(LoginDate) values('2018-05-01'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable(LoginDate) values('2017-12-31'); Query OK, 1 row affected (0.12 sec)Display all records from the table using select statement ...
Read MoreCan we use Switch statement with Strings in java?
A switch statement allows a variable to be tested for equality against a list of values. Each value is called a case, and the variable being switched on is checked for each case.Syntaxswitch(expression) { case value : // Statements break; case value : // Statements break; // You can have any number of case statements. default : // Statements }Strings in switchYes, we can use a switch statement with Strings in Java. While doing so you need ...
Read MoreHow to change JButton font dynamically in Java?
The following is an example to change JButton font dynamically:Exampleimport java.awt.Font; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; public class SwingDemo extends JFrame { JButton button = new JButton("Change"); int fontSize = 10; public SwingDemo() { setSize(500, 400); setDefaultCloseOperation(EXIT_ON_CLOSE); add(button); // changing font size dynamically on button click button.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent ev) { button.setFont(new Font("Dialog", Font.PLAIN, ++fontSize)); button.revalidate(); } }); setVisible(true); } public static void main(String[] args) { new SwingDemo(); } }OutputClick “Change” button above to change the font:
Read MoreC++ Program to Find the Number of Ways to Write a Number as the Sum of Numbers Smaller than Itself
In this program we will count the number of ways one number can be represented by sum of numbers smaller than itself. This program will count the partition of given numbers. We take a number n as input, then starting from a number break it by removing 1 at a time. If the new partition is generated, increase the counter.AlgorithmpartitionCount(n)Input : The number nOutput : The number of partitionsBegin Create array p of size n k := 0 count := -1 put n as the first element of array p Repeat the following steps, do ...
Read MoreHow to perform SELECT using COUNT in MySQL?
To perform SELECT with COUNT, use aggregate function COUNT(). Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Name varchar(100), Subject varchar(100) ); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Name, Subject) values('John', 'MySQL'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(Name, Subject) values('John', 'Java'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(Name, Subject) values('Carol', 'MongoDB'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(Name, Subject) values('Carol', ...
Read MoreDifference between files written in binary and text mode in C++
Text modeBinary modeIn text mode various character translations are performed i.e;“\r+\f” is converted into “”In binary mode, such translations are not performed.To write in the files:ofstream ofs (“file.txt”);Orofstream ofs;ofs.open(“file.txt”);to write in the files: ofstream ofs(“file.txt”, ios::binary);orofstream ofs;ofs.open(“file.txt”, ios::binary);To add text at the end of the file:Ofstream ofs(“file.txt”, ios::app);orofstream ofs;ofs.open(“file.txt”, ios::app);To add text at the end of the file:Ofstreamofs(“file.txt”, ios::app|ios::binary);or ofstream ofs;ofs.open(“file.txt”, ios::app|ios::binary);To read files:ifstream in (“file.txt”);orifstreamin ; in.open(“file.txt”);To read files: ifstream in (“file.txt”, ios::binary);orifstream in ;in.open(“file.txt”, ios::binary);
Read MoreHow to make notification intent resume rather than making a new intent?
This example demonstrate about How to make notification intent resume rather than making a new intentStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml. Step 3 − Add the following code to src/MainActivity.javapackage app.tutorialspoint.com.notifyme ; import android.app.NotificationChannel ; import android.app.NotificationManager ; import android.app.PendingIntent ; import android.content.Context ; import android.content.Intent ; import android.support.v4.app.NotificationCompat ; import android.support.v7.app.AppCompatActivity ; import android.os.Bundle ; import android.view.View ; import android.widget.Button ; public class MainActivity extends AppCompatActivity { ...
Read MoreHow to implement constants in java?
A constant variable is the one whose value is fixed and only one copy of it exists in the program. Once you declare a constant variable and assign value to it, you cannot change its value again throughout the program.You can create a constant in c language using the constant keyword (one way to create it) as −const int intererConstant = 100; or, const float floatConstant = 16.254; ….. etcConstants in javaUnlike in C language constants are not supported in Java(directly). But, you can still create a constant by declaring a variable static and final.Static − Once you declare a ...
Read MoreHow to disable JCheckBox if not checked in Java
The following is an example to disable JCheckBox if not checked in Java:Exampleimport java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JCheckBox; import javax.swing.JOptionPane; public class SwingDemo { public static void main(String[] args) { JCheckBox checkBox = new JCheckBox("Demo", true); checkBox.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { if (checkBox.isEnabled()) checkBox.setEnabled(false); else checkBox.setEnabled(true); } }); JOptionPane.showMessageDialog(null, checkBox); } }OutputNow, when you will uncheck the above checkbox, it will get disabled:
Read MoreJava DatabaseMetaData supportsBatchUpdates() method with example
The supportsBatchUpdates() method of the DatabaseMetaData interface is used to determine whether the underlying database supports batch updates.This method returns a boolean value which is −True, when the underlying database supports stored porcedures.False, when the underlying database doesn't support stored porcedures.To determine whether the underlying database supports stored porcedures −Make sure your database is up and running.Register the driver using the registerDriver() method of the DriverManager class. Pass an object of the driver class corresponding to the underlying database.Get the connection object using the getConnection() method of the DriverManager class. Pass the URL the database and, user name, password of ...
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