数据库 mysql 散列密码

Question

so I'm trying to hash some passwords from a database from a login form and when I try first time to login it works with the password from database then I hash it with MD5 then when I come back to the login page I want to put the previously used password to log me in but it changed to the MD5 one. Is there any solution to have the MD5 one in the database and me to login with the first used?Thanks in advance (smecher.j is a variable who is 0)

public void validateLogin(){
    DatabaseConnection connectNow = new DatabaseConnection();
    DatabaseConnection connectNow2 = new DatabaseConnection();

    Connection connectDB = connectNow.getConnection();
    Connection connectDB2 = connectNow2.getConnection();


    String verifyLogin = " SELECT count(1) FROM user_account WHERE username = '" + usernameTextField.getText()  + "' AND password ='" + enterPasswordField.getText() +"'";
    String insertFields3 = " UPDATE user_account SET password = MD5(password) WHERE username = '" + usernameTextField.getText() +"'";

    try{
        Statement statement  = connectDB.createStatement();
        Statement statement2  = connectDB2.createStatement();

        ResultSet queryResult = statement.executeQuery(verifyLogin);
        while(queryResult.next()){
            if(queryResult.getInt(1)==1){
                login1();
                if(smecher.j==0) {
                    statement2.executeUpdate(insertFields3);
                    smecher.j++;
                }

                text1=enterPasswordField.getText();
            }else{
                loginMessageLabel.setText("Invalid login, please try again");
            }

        }
        lol();
    }catch(Exception e){
        e.printStackTrace();
        e.getCause();
    }

}
public static String text1 = "";
public void lol() {
    Connection conn = null;
    Statement st = null;
    ResultSet rs = null;

    String dbUrl = "jdbc:mysql://localhost:3306/databaselol?autoReconnect=true&useSSL=false";
    String dbUsr = "root";
    String dbPass = "!Iloriana12";
    try {
        String sql = "SELECT password FROM user_account where username  = '" + usernameTextField.getText() + "'";
        Class.forName("com.mysql.cj.jdbc.Driver");
        conn = DriverManager.getConnection(dbUrl, dbUsr, dbPass);
        st = conn.createStatement();
        rs = st.executeQuery(sql);

        while(rs.next()){
            String value = rs.getString("password");
            text1 =value;
        }
        System.out.println(text1);

    }catch(Exception e){
        e.printStackTrace();
    }finally{
        try {
            rs.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        try {
            st.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        try {
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

Answer 1

when saving password you should save it encrypted and when you verify the password you should verify comparing the encrypted versions of the password as in.

String verifyLogin = " SELECT count(1) FROM user_account WHERE username = '" + usernameTextField.getText()  + "' AND password =MD5('" + enterPasswordField.getText() +"')";

String insertFields3 = " UPDATE user_account SET password = MD5('" + enterPasswordField.getText() + "') WHERE username = '" + usernameTextField.getText() +"'";