This tutorial will teach you Simple Sales Inventory System in Java and mysql.this example which will help you to learn the auto no generating using by the code.



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/vmproducts","root","");
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
} catch (SQLException ex) {
ex.printStackTrace();
}
}Second Step :- Create the Function getBillNo for generating the Auto ID.
public int getBillNo()
{
int billno = 1;
try {
Statement smt = con.createStatement();
ResultSet rs = smt.executeQuery("select max(billno) from sales");
rs.next();
billno = rs.getInt(1) + 1; // increment by 1 auto ID Set
rs.close();
} catch (SQLException ex) {
ex.printStackTrace();
}
return billno;
}After fill the productname,salesqty,customer click addbutton record will be added in to the database.
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
try {
String billno = txtbillno.getText();
String date = txtdate.getText();
String pname = txtpname.getText();
String qty = txtqty.getText();
String customer = txtcustomer.getText();
pst = con.prepareStatement("insert into sales(billno,salesdate,prodname,qty,customer)values(?,?,?,?,?)");
pst.setString(1, billno);
pst.setString(2, date);
pst.setString(3, pname);
pst.setString(4, qty);
pst.setString(5, customer);
int status = pst.executeUpdate();
if(status==1)
{
JOptionPane.showMessageDialog(this, "Sales Completedddddd");
txtpname.setText("");
txtqty.setText("");
txtcustomer.setText("");
txtpname.requestFocus();
txtbillno.setText(String.valueOf(getBillNo())); //after sales successfully Auto ID increment by 1
}
else
{
JOptionPane.showMessageDialog(this, "Sales Failedddd!!!");
}
} catch (SQLException ex) {
ex.printStackTrace();
}
}I have attached the video tutorial below it will help you to do this step by step.