Question

PreparedStatement preparedStatement = Connectionstring().prepareStatement(
            "Select Username from dbo.LoginDetails where Username = ? and Password =?");
  String User = tf_Fname.getText();
  String _Pass = new String(tf_Lname.getPassword());
        preparedStatement.setString(1, User);
        preparedStatement.setString(2, _Pass);
        ResultSet resultSet = preparedStatement.executeQuery();
        while (resultSet.next()) 
        {
            System.out.println("Username is "+ resultSet.getString(1)+"Password is "+resultSet.getString(2));  
        }

没有

+"Password is "+resultSet.getString(2)

它工作正常，它是从数据库打印用户名但是，这也会引发错误。

com.microsoft.sqlserver.jdbc.SQLServerException: The index 2 is out of range.

Answer 1

Select Username from .....................

select子句中只有一列。

将其更改为

  Select Username, yourpasswordcolumnname from......

Answer 2

您只从表中检索一列：

"Select Username from dbo.LoginDetails where Username = ? and Password =?");

试试这个：

 "Select Username, Password from dbo.LoginDetails where Username = ? and Password =?");

然后你的代码应该工作，在另一个相关的注释，永远不要存储密码为＆＃34;明文＆＃34;，总是使用单向加密方法，并使用盐！

相关：You're Probably Storing Passwords Incorrectly

Answer 3

select * from dbo.LoginDetails where Username = ? and Password =?

将为您提供所需的信息，以便您选择dbo.LoginDetails中的所有列，而不只是选择一列，Username，就像您现在一样

指数2超出范围

3 个答案: