Invoice No Generating using Java and Mysql

This tutorial will teach you how to generating Auto Invoice No using Java and Mysql.this example will important for developing the inventory management system project.

FirstStep : we have to establish the database connection

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

    }

Second Step :- Create the Function invoiceid paste code.

public void invoiceid()
    {
        try {
           
            Statement s = con.createStatement();
            ResultSet rs = s.executeQuery("SELECT MAX(invoiceid) FROM sales");
            rs.next();
            rs.getString("MAX(invoiceid)");
            if (rs.getString("MAX(invoiceid)") == null) {
                txtid.setText("E-0000001");     
            } else {
                long id = Long.parseLong(rs.getString("MAX(invoiceid)").substring(2, rs.getString("MAX(invoiceid)").length()));
                id++;
                txtid.setText("E-" + String.format("%07d", id));
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }      
    }

After fill the productname,price click addbutton record will be added in to the database.

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         

            String id =txtid.getText();
            String fname =txtname.getText();
            String price =txtprice.getText();
           
       
        try {
            pst = con.prepareStatement("insert into sales(invoiceid,prodname,price)values(?,?,?)");
            pst.setString(1,id);
            pst.setString(2,fname);
            pst.setString(3,price);
           
            pst.executeUpdate();
            JOptionPane.showMessageDialog(this, "order completed"); 
            
            
            invoiceid();
            
            txtname.setText("");
            txtprice.setText("");
            txtname.requestFocus();
            
            
        } catch (SQLException ex) {
            Logger.getLogger(invoice.class.getName()).log(Level.SEVERE, null, ex);
        }  
    }