How to retrieve items from database table in JAVA using Netbeans

In this article i will explain you, how to retrieve items from database table in Java using Netbeans. In previous article, we have already learned, how to create connection with the derby database using netbeans. Before reading this article, please must to see the previous article for implementations. In this article, i only explain you, how to use executeQuery( ) method and select statement in java.

--How to create connection with database full video tutorial 


Code :

class abc {
    public abc() throws SQLException
    {
        Connection conn=DriverManager.getConnection("jdbc:derby://localhost:1527/student", "tarun", "tarun");
        System.out.println("Connection Created");
        Statement st=conn.createStatement();
        ResultSet rs=st.executeQuery("select * from USERTABLE");
        while(rs.next())
        {
            System.out.println(rs.getString(2));
        }
   
    }

}

Here, we have a table i.e USERTABLE. If you want to learn how to create table in exists database using Netbeans. Read mentioned steps:
Step-1 :  Right click on Connection String, select "connect" from popup menu.
Step-2 :  Expand username which contains Tables, views and stored procedure.
Step-3 :   Right click on table, select create table.

Write the name of table also add columns with their datatypes. 

How to create Database connection in JAVA using Netbeans

If you want to connect database with your java application then first to need a database. First to create database using Netbeans services tab. This tab available under Windows tab. You can also select this tab by using shortcut CTRL+ 5.

1. Expand the databases tab, select "Create Database." option. 

2. Fill fields which are shown under diagram.

 3. After filling the form, you have to create database successfully.
 4. Right Click on your connection string name, select properties for copy the database URL.

5. Copy Database URL, which is used further.

6. Create a new java project under projects tab. 

7. Add a Library in the "Libraries" section of your project.

8. Select Java DB Driver under Add Library section.

9. Open your .java file which is exists in java packages folder of your project. 

10. Create a another class object, which is exists in same package.

11. Now, Open the object class, create constructor in it.

12. paste the code under the constructor.

Connection conn=DriverManager.getConnection("jdbc:derby://localhost:1527/jk", "jk", "jk");

        System.out.println("connection created"); 

Here we have three parameters in getConnection method. 

First refer to database url ; according to 5th step.

Second : Username 

Third :  password.

AWT Frame close using close Button

In AWT Java we have a Frame class which is inherit from window class. If you are a beginner in AWT Java then you know that Frame doesn't close when we press close button of it. So, In last we pressed stop debugging button in Netbeans IDE. If you want to close Frame using Close button, which is see in top right corner of Frame then you should implement code for it. 

Complete Java Code


package awtframe;

import java.awt.Frame;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;


public class AWTFrame {

    public AWTFrame()
    {
        Frame f1=new Frame("Welcome to Closing");
        f1.setSize(500,500);
        f1.setVisible(true);
       
        f1.addWindowListener(new WindowAdapter(){
           
            @Override
            public void windowClosing(WindowEvent e)
            {
              System.exit(0);
            }
           
        });
       
       
    }
    public static void main(String[] args) {
     
       AWTFrame at=new AWTFrame();
       
    }
   
}

Here, we have windowClosing ( ) method to close Frame using close button.