Username ,Password Validation

chdboy

I want to validate Username and Password matching from my sql Database,but it didn't work.Even if the text fields are blank it does not give any error.

private static void selectfromdb() throws SQLException
{
Statement stmt = Connectionstring().createStatement();
ResultSet rs = stmt.executeQuery("SELECT Username,Password FROM LoginDetails where Username='"+tf_Fname+"' AND Password ='"+tf_Lname+"'");
while (rs.next())
{
String x = tf_Fname.getText();
String pass = new String(tf_Lname.getPassword());
if (x.equals(rs.getString("Username")))
{
if (pass.equals(rs.getString("Password")))
{
JOptionPane.showMessageDialog(null,"Login Successful! ","Success",JOptionPane.WARNING_MESSAGE);
//System.out.println("Logged in!");
}
else
{
JOptionPane.showMessageDialog(null,"Login UNSuccessful! ","UNSuccessful",JOptionPane.WARNING_MESSAGE);
// System.out.println("Password did not match username!");
}
}
}

Blue_Boy

Try this

private static void selectfromdb() throws SQLException
{
Statement stmt = Connectionstring().createStatement();
ResultSet rs = stmt.executeQuery("SELECT Username,Password FROM LoginDetails where Username='"+tf_Fname+"' AND Password ='"+tf_Lname+"'");

 rs.last();
int rowcount = rs.getRow();
if(rowcount ==0){
JOptionPane.showMessageDialog(null,"Login UNSuccessful! ","UNSuccessful",JOptionPane.WARNING\_MESSAGE);
}
else{
	JOptionPane.showMessageDialog(null,"Login Successful! ","Success",JOptionPane.WARNING\_MESSAGE);
}

}

I Love T-SQL "VB.NET is developed with C#.NET" If my post helps you kindly save my time by voting my post.

Lost User

Blue_Boy wrote:

  ResultSet rs = stmt.executeQuery("SELECT Username,Password FROM LoginDetails where Username='"+tf\_Fname+"' AND Password ='"+tf\_Lname+"'");

It is really bad form to give sample code that can lead to SQL injection[^].

Use the best guess

Blue_Boy

I didn't gave example to use query which is able to inject, the user used by him/herself, i just gave solution how to manage login case.

I Love T-SQL "VB.NET is developed with C#.NET" If my post helps you kindly save my time by voting my post.

chdboy

In both the cases even if it's right password it shows "Login UNSuccessful"

Lost User

Use your debugger to step through the code and see what values your variables contain at each stage.

Use the best guess

jschell

So the code is telling you the values are not equal. Figure out what the values are and you will see the difference. Either a debugger or a print them out. But as a guess there is a case difference. The query doesn't care but the comparison does.

chdboy

The row count is 0 when I debug it....but I'm using the same username and password what's in the database,why is it not accepting it?

Lost User

chdboy wrote:

The row count is 0 when I debug it....but I'm using the same username and password what's in the database,why is it not accepting it?

I have no idea since I have no access to your system. You need to investigate further to discover what is happening.

Use the best guess

chdboy

com.microsoft.sqlserver.jdbc.SQLServerException: The result set has no current row.

But when I see it in the Database there are plenty of rows. I don't understand why it is not picking up the rows ?

chdboy

Now I have changed the code

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));
}

But now it's picking up the right Username from the table ,if I don't use

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

in the Print line,and if I use that I get an error

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

Lost User

I guess that you need to look more closely at the contents of your ResultSet and its individual property items. Check with your debugger and also the documentation for the classes that you are working with.

Use the best guess

chdboy

I think I got what is wrong with it.....I'm missing Select Username,Password ...hehe thanks