JDBC Sales Inventory System Java

This tutorial will teach you JDBC Sales Inventory System step by step.

First Step : The System shall be able to find product information.Enter the relavent product id on the product id textfield to find the product information.relavent product information will be displayed on the below textfields.
select the productid textfield right click and Add event handler->key->keyPressed

import the namespace : import java.sql.*;

Establish the database connection.

Connection con;
PreparedStatement pst;
 
public void Connect()
{
        try 
        {
            Class.forName("com.mysql.jdbc.Driver");
            con = DriverManager.getConnection("jdbc:mysql://localhost/wijproducts", "root","");
        }
        catch (ClassNotFoundException ex) 
        {
          ex.printStackTrace();
        }
        catch (SQLException ex) 
        {
          ex.printStackTrace();
        }

}

Database

Paste the code inside the keyReleased Event

public void keyReleased(KeyEvent e) 
{
     String pid = txtpid.getText();
 try
         {
    pst = con.prepareStatement("SELECT * from products where id=?");
    pst.setString(1,pid);
     
     ResultSet rs1=pst.executeQuery();

     if(rs1.next()==false)
  {
    JOptionPane.showMessageDialog(null,"Product ID not found!");
     txtpname.setText("");
     txtprice.setText("");
      txtpid.requestFocus();
   }
  else
  {
    String pname = rs1.getString(2);
    String price = rs1.getString(3);
    String dis = rs1.getString(5);
    txtpname.setText(pname.trim());
     txtprice.setText(price);
     txtdis.setText(dis);
     
    }
               } 
              catch (SQLException e1) 
              { 
  e1.printStackTrace();
        }
}

Paste the code inside the Ok button

public void actionPerformed(ActionEvent e) 
{
 
    String pid = txtpid.getText();
    double qty = Double.parseDouble((txtqty.getText()));
    double price = Double.parseDouble((txtprice.getText()));
    double discount = Double.parseDouble((txtdis.getText()));
          
 try 
     {
 pst = con.prepareStatement("select sum(cast(round((?*? * ?/100),2) as decimal(19,2))) as discount from products where id=?");    
        //select sum(cast(round((price*qty * discount/100),2) as decimal(19,2))) as discount from products where id=?
 pst.setDouble(1,price);
 pst.setDouble(2,qty);
 pst.setDouble(3,discount);
 pst.setString(4,pid);
     
 ResultSet rs1=pst.executeQuery();
 rs1.next();
   
 double discountamount = Double.parseDouble((rs1.getString("discount")));
  
 lbldis.setText(String.valueOf(discountamount));
     
 double subtot =  price * qty - discountamount; 
     
 lblsubtot.setText(String.valueOf(subtot));
 
 }
 catch (SQLException e1) 
{
     
 e1.printStackTrace();
}
}