SQL 登录验证 - 检查用户类型

Question

下面的程序当前检查用户的登录详细信息是否正确。然后进入下一部分，检查用户是否是管理员。目前我正在尝试通过所有普通用户在我的数据库中列为 'user_admin' [null] 而管理员将在数据库中列为 1 来解决这个问题。我环顾四周，似乎没有人用我正在做的方法问过与此相关的问题。

如果您查看我的代码，您会发现普通用户应指向 UserPanel，而管理员应指向 AdminPanel。这是因为我的程序设置为人们可以查看那里的帐户，而管理员可以编辑帐户。

这是我正在从事的拼贴项目，因此该程序非常简单。

JLabel lblNewLabel = new JLabel("");
    lblNewLabel.setIcon(new ImageIcon(PanelLogin.class.getResource("/image/Login.png")));
    lblNewLabel.setBounds(118, 115, 100, 26);
    lblNewLabel.addMouseListener(new MouseAdapter() {
        @Override
        public void mouseEntered(MouseEvent e) {
            lblNewLabel.setIcon(new ImageIcon(PanelLogin.class.getResource("/image/Loginv2.png")));
        }
        @Override
        public void mouseExited(MouseEvent e) {
            lblNewLabel.setIcon(new ImageIcon(PanelLogin.class.getResource("/image/Login.png")));
        }
        @Override
        public void mouseClicked(MouseEvent e) {
            if (LoginAttempts < 3 ) {
            try {
                String Host = "removed";
                String Name = "removed";
                String Pass = "removed";

                Connection conn = DriverManager.getConnection( Host, Name, Pass );  
                PreparedStatement pst = conn.prepareStatement("SELECT `user_name`, `user_pass` FROM `table_1` WHERE `user_name` = ? AND `user_pass` = ?");
                pst.setString(1, textID.getText());
                pst.setString(2, String.valueOf(passwordField.getPassword()));
                ResultSet Result = pst.executeQuery();
                if (Result.next()) {
                    String user =Result.getString("user_name");
                    try {
                        PreparedStatement pst2 = conn.prepareStatement("SELECT `user_admin` FROM `table_1` WHERE `user_name` = ?");
                        pst2.setString(1, user);
                        if (Result.next()) {
                            frmLotusLogin.dispose();
                            new UserPanel(user).frame.setVisible(true);
                        }
                        else {
                            frmLotusLogin.dispose();
                            new AdminPanelMain(user).frmLotusSecurity.setVisible(true);
                        }

                    }
                    catch (Exception exc){

                    }
                }
                else {
                    JOptionPane.showMessageDialog(null, "Incorrect Username/Password");
                    LoginAttempts = LoginAttempts + 1;
                }
            }
            catch (Exception ex) {
                System.out.println(ex);
                JOptionPane.showMessageDialog(null, "An error occurred. Your Username/Password could be incorrect, "
                        + "If error contiues to appear please contact support! Error Number: L1");
            }
            }
            else {
                JOptionPane.showMessageDialog(null, "You Have Entered The Wrong Password Too Many Times, You are now locked out!");
            }
        }
    });

提前感谢发现我做错了什么或需要更改以使其正确验证的任何人。如果有人需要任何进一步的信息，请随时询问。

第一次建议后

try {
                String Host = "";
                String Name = "";
                String Pass = "";

                Connection conn = DriverManager.getConnection( Host, Name, Pass );  
                PreparedStatement pst = conn.prepareStatement("SELECT `user_name`, `user_pass` FROM `table_1` WHERE `user_name` = ? AND `user_pass` = ?");
                pst.setString(1, textID.getText());
                pst.setString(2, String.valueOf(passwordField.getPassword()));
                ResultSet Result = pst.executeQuery();
                    if (Result.next()) {
                        String user = Result.getString("user_name");
                        try {
                            PreparedStatement pst2 = conn.prepareStatement("SELECT `user_admin` FROM `table_1` WHERE `user_name` = ?");
                            pst2.setString(1, user);
                            ResultSet Result2 = pst2.executeQuery();  // added
                            if (Result2.next()) { // modified
                                System.out.println("Test");
                                frmLotusLogin.dispose();
                                new UserPanel(user).frame.setVisible(true);
                            } else {
                                frmLotusLogin.dispose();
                                new AdminPanelMain(user).frmLotusSecurity.setVisible(true);
                            }

                        } catch (Exception exc) {

                          // do something here !

                        }
                }
                else {
                    JOptionPane.showMessageDialog(null, "Incorrect Username/Password");
                    LoginAttempts = LoginAttempts + 1;
                }
            }
            catch (Exception ex) {
                System.out.println(ex);
                JOptionPane.showMessageDialog(null, "An error occurred. Your Username/Password could be incorrect, "
                        + "If error contiues to appear please contact support! Error Number: L1");
            }
            }
            else {
                JOptionPane.showMessageDialog(null, "You Have Entered The Wrong Password Too Many Times, You are now locked out!");
            }
        }
    });

这就是我的 table 目前的样子你可以看到我正在做什么来说明用户是否是管理员

Answer 1

您永远不会执行第二条语句，当然也不会使用它的结果（因为您仍然使用第一个结果集）。

此外，在捕获异常时永远不要忽略它们，除非您确定它根本不重要。

最后，您应该在完成后关闭 statements/connections（我没有将这部分添加到下面的代码中）。

        ResultSet Result = pst.executeQuery();
        if (Result.next()) {
            String user = Result.getString("user_name");
            try {
                PreparedStatement pst2 = conn
                        .prepareStatement("SELECT `user_admin` FROM `table_1` WHERE `user_name` = ? AND `user_admin` = 1");

                pst2.setString(1, user);
                ResultSet Result2 = pst2.executeQuery();  // added
                if (Result2.next()) { // modified
                    frmLotusLogin.dispose();
                    new AdminPanel(user).frame.setVisible(true);
                } else {
                    frmLotusLogin.dispose();
                    new MainUserPanel(user).frmLotusSecurity.setVisible(true);
                }

            } catch (Exception exc) {

              // do something here !

            }

SQL 登录验证 - 检查用户类型

SQL Login Verification - Checking user Type

java

mysql

sql

login

verification