// Declaring database connection settings.. *java* is the database name, hence all operations will be performed in this db.

String url = "jdbc:mysql://localhost:3306/java";
String user = "root";
String pw = "";



/* You implement an action listener to the button Delete (btnDelete) which defines what should be done when a user performs certain *operation.. The operation may be when a user clicks a button, chooses a menu item or presses Enter in a text field.
* The actionPerformed is the method that executes the action when a user clicks the button (btnDelete). Here you are deleting a supplier.

        btnDelete.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {

                try {

                    Class.forName("com.mysql.jdbc.Driver"); //register the JDBC Driver

                    Connection con = DriverManager.getConnection(url, user, pw); //establish the db connection

                    String del = "DELETE FROM supplier WHERE SupplierID = ?"; // SQL Query to delete the a supplier by a Supplier ID

                    PreparedStatement pstmt = con.prepareStatement(del); // using a prepared statement to achieve this

                    int id =   Integer.parseInt(txtSupplierId.getText()); // get the supplier ID from the text field. Since the ID is an Integer in the DB, the textfield returns us the ID as a String. Hence, we convert it to Integer using Integer.parseInt(...

                    pstmt.setInt(1, id); // we set the parameter index from the SQL Query where there is a ? in the SQL Query above

                    pstmt.execute(); // runs the query within java

                JOptionPane.showMessageDialog(null, "Deleted"); // display a successful msg if deleted./
                } catch (Exception err) {
                    JOptionPane.showMessageDialog(Supplier.this, err.getMessage()); // catches the error if the delete is not successful..
                }

            }
        });