problem with 'if else' in c# winform

Question

1.00/5 (2 votes)

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hi friends;
i am having a problem working with my loging form which i design in winform here is my code

C#

private void btnLogin_Click(object sender, EventArgs e)
      {
          user = txtUsername.Text;
          pass = txtPassword.Text;
          role = cbRole.Text;
          SqlConnection con = new SqlConnection();
          con.ConnectionString = "Data Source=ESE-HP;Initial Catalog=PIMS;User ID=sa;PWD=ese";
          con.Open();
          SqlCommand cmd = new SqlCommand("select * from employee where  occupation = '" + role + "' and password = '" + pass + "' and username = '" + user + "' ", con);
          SqlDataReader dr = cmd.ExecuteReader();


          while (dr.Read())
          {
              if ((dr["Password"].ToString() == pass && dr["Username"].ToString() == user && dr["Occupation"].ToString() == role))
              {
                  messageBox.Show("Login Successful");
              }

             else
              {
                  MessageBox.Show("LOGIN NOT SUCCESSFUL );
              }
            }
      }

i have a login form that has username, password and role textbox when i run the code and enter my correct credentials, it displays the message "LOGIN SUCCESSFUL", but if i did not enter the correct information in the boxes, it wont display the 'else' message which is "LOGIN NOT SUCCESSFUL", i do not know what the problem is, can someone help me out? thanks.

Posted 18-Nov-12 11:44am

Ese Ochuko

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Comments

Sergey Alexandrovich Kryukov 18-Nov-12 18:09pm

Do you use the debugger? This is what you always need before asking such questions, and in fact, usually -- instead of. :-)
--SA

3 solutions

Solution 4

Try this:

private void btnLogin_Click(object sender, EventArgs e)
{
            user = txtUsername.Text;
            pass = txtPassword.Text;
            role = cbRole.Text;
            SqlConnection con = new SqlConnection();
            con.ConnectionString = "Data Source=ESE-HP;Initial Catalog=PIMS;User ID=sa;PWD=ese";
            con.Open();
            SqlCommand cmd = new SqlCommand("select * from employee where  occupation = '" + role + "' and password = '" + pass + "' and username = '" + user + "' ", con);
            SqlDataReader dr = cmd.ExecuteReader();
 

if (dr != null)messageBox.Show("Login Successful");
else MessageBox.Show("LOGIN NOT SUCCESSFUL );
 
}

Posted 18-Nov-12 18:09pm

Subrata.In

Solution 1

Try this
use try catch block, and get the database credentials informations in variable before compare them to the user input and try to use & rather than &&

Posted 18-Nov-12 11:52am

Jean-Claude ADIBA

Comments

Ese Ochuko 18-Nov-12 18:25pm

Still not working

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CPallini · Accepted Answer · 2012-11-18T12:25:00

You are redundantly checking the passed credentials: the first time with the SQL query, the second time with code inside the loop.
You might change

Quote:
while (dr.Read())
{
if ((dr["Password"].ToString() == pass && dr["Username"].ToString() == user && dr["Occupation"].ToString() == role))
{
messageBox.Show("Login Successful");
}

else
{
MessageBox.Show("LOGIN NOT SUCCESSFUL );
}
}

to

C#

if ( dr.hasRows )
  messageBox.Show("Login Successful");
else
  messageBox.Show("LOGIN NOT SUCCESSFUL");