Invalid attempt to read when no data is present

Abdullaziz Said said

hello
i write c# code to check if the user type = 1 depended on value comes from datareader
but i got this error Invalid attempt to read when no data is present

this is my code

protected void Page_Load(object sender, EventArgs e)
    {
        string name = "";
        if (Session["usernames"] != "" & Session["usernames"] != null)
        {
            name = Session["usernames"].ToString();
            SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["soom_dbConnectionString"].ConnectionString);
            SqlCommand command = new SqlCommand("SELECT user_type FROM dbo.user_data where user_name='" + name + "'");
            command.Connection = connection;
            command.CommandType = CommandType.Text;
            connection.Open();
            SqlDataReader reader = command.ExecuteReader(CommandBehavior.CloseConnection);
            if (reader.HasRows)
            {
                if (reader["user_type"] == "1")
                {
                    Response.Redirect("../admincp/Default.aspx");
                }
                else
                {
                    Response.Redirect("../Access_Denied.aspx");
                }
            }
           
                
        }
        
       
    }

and use this code also

string name = "";

if (Session["usernames"] != "" & Session["usernames"] != null)

 { name = Session["usernames"].ToString();

 SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["soom_dbConnectionString"].ConnectionString);

 SqlCommand command = new SqlCommand("SELECT user_type FROM user_data where user_name='"+name+"'");

 command.Connection = connection;

 command.CommandType = CommandType.Text;

 connection.Open(); SqlDataReader reader = command.ExecuteReader(CommandBehavior.CloseConnection);

 if (reader.HasRows) {

  reader.Read();

  if (reader["user_type"]== "1")

{ Response.Redirect("../admincp/Default.aspx");

   } else

{ Response.Redirect("../Access_Denied.aspx");

 
 
when i use this code and iam sure that the user_type value is 1 it's redirect me to access_denied.aspx idk Why
and when i change the code to

string name = "";
 if (Session["usernames"] != "" & Session["usernames"] != null)
 { name = Session["usernames"].ToString();
 SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["soom_dbConnectionString"].ConnectionString);
 SqlCommand command = new SqlCommand("SELECT user_type FROM user_data where user_name='"+name+"'");
 command.Connection = connection; 
command.CommandType = CommandType.Text; 
connection.Open(); 
SqlDataReader reader = command.ExecuteReader(CommandBehavior.CloseConnection); 
if (reader.HasRows)
 {   reader.Read(); string type = reader["user_type"].ToString(); 
if (type == "1") 
{ Response.Redirect("../admincp/Default.aspx");
 } else
 { Response.Redirect("../Access_Denied.aspx"); 
 } 
}
 
i enter infinite loop 
waiting for the best answer
thanks in advance

8 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes12y ago
Accepted answer
Try replacing this line:

Response.Redirect("../admincp/Default.aspx");

with this one:

if(!HttpContext.Current.Request.Path.EndsWith("/admincp/Default.aspx", StringComparison.InvariantCultureIgnoreCase))
Response.Redirect("../admincp/Default.aspx"));
Abdullaziz Said said12y ago
no i don't
Vulpes12y ago
Yes, there must be something else in your code that is causing this redirection.

Are you doing any authentication anywhere?
Abdullaziz Said said12y ago
there are another problem :( all pages redirect to the http://localhost:57703/admincp/Default.aspx

all pages
BTW this code in the admin masterpage :'(
Vulpes12y ago
I figured that there was already something in you application (perhaps forms authentication) which was already redirecting automatically to that page, thereby setting up a redirect loop.

So basically we just checked if that was the case and only redirected to that page if it wasn't.
Abdullaziz Said said12y ago
thanks :D it's work but can you plz explain me the answer
thanks in advance
Abdullaziz Said said12y ago
the same error :(
This webpage has a redirect loop
Vulpes12y ago
Well, I think the final piece of code is the one to go for, but I'd try a slightly different formulation by replacing this bit:

if (reader.HasRows)
{
reader.Read(); string type = reader["user_type"].ToString();
if (type == "1")
{
Response.Redirect("../admincp/Default.aspx");
}
else
{
Response.Redirect("../Access_Denied.aspx");
}
}

with this:

string type = null;

if (reader.Read())
{
type = reader["user_type"].ToString().Trim();
}

reader.Close(); // also closes connection

if (type == "1")
{
Response.Redirect("../admincp/Default.aspx");
}
else
{
Response.Redirect("../Access_Denied.aspx");
}

Invalid attempt to read when no data is present

This webpage has a redirect loop