Input string was not in a correct format c# and asp.net

Question

I'm working on a simple asp.net log in page. a simple code when user log in it verifies with the sql and direct to the page for either staff or admin. but i have this error (int.Parse(myReader.ToString()) > 0) ... Input string was not in a correct format my code..

string Connection = "Data Source=(ip);Initial Catalog=..;Persist Security Info=True;User ID=(id);Password=(pass)";
SqlConnection myConn = new SqlConnection(Connection);

SqlCommand SelectCommand = new SqlCommand("select * from tar_login where Username ='" + txtUsername.Text + "' and Password='" + txtPassword.Text + "' and Position='" + ddlPosition.Text + "';", myConn);

myConn.Open();

var myReader = SelectCommand.ExecuteScalar();
myConn.Close();

if (myReader != null)
{
    if (int.Parse(myReader.ToString()) > 0)
    {
        if (ddlPosition.Text == "Admin")
        {
            Response.Redirect("manager.aspx");
        }
    }
}

if (myReader != null)
{
    if (int.Parse(myReader.ToString()) > 0)
    {
        if (ddlPosition.Text == "Staff")
        {
            Response.Redirect("staff.aspx");
        }
    }
}

else
{
    Label1.ForeColor = System.Drawing.Color.Red;
    Label1.Text = "Incorrect. Please try again";
    myConn.Close();
}

.help as im new to asp.net and c#

it means that `myReader.ToString()` was not a number, or not in a format that is an int. — Noctis, Aug 30 '14 at 06:55
debug your code, add a breakpoint at `var myReader = SelectCommand.ExecuteScalar();` and check what's it's value, may be not integer or null — Farrokh, Aug 30 '14 at 06:57

Noctis · Answer 1 · 2014-08-30T08:02:10.960

The ExecuteScalar returns an object (the row), or null.
Then you try to ToString it. Unless you return only one column, which is an int, this will not be something that int.Parse will be able to parse.

You can try int.TryParse, but it'll return false I believe. What do you have in myReader if you put a breakpoint in there? it might give you/us a better understanding about what you're dealing with.

Edit:

o_O ?!

You have two clauses saying : if (myReader != null). Merge them.

Whenever you work with DB's or any resource you need to handle, use using, like Saunders suggested.

Other than that, you answered your question. If you get a null back, it cannot be parsed into an int.

You'll have to figure out your DB issues or your query, and try again.

score 0 · Answer 2 · answered Aug 30 '14 at 08:19

0

Your ExecuteScalar() is bringing a non-numeric character (e.g. 'A'), which cannot be converted to integer.

It seems in your code there is no need of checking > 0.

myReader != null is sufficient.

Whatever Samiey has suggested above looks perfect.

answered Aug 30 '14 at 08:19

Vic

21
2

score 0 · Answer 3 · answered Aug 30 '14 at 08:56

Try This Code

    string Connection = "Data Source=(ip);Initial Catalog=..;Persist Security Info=True;User ID=(id);Password=(pass)";
    SqlConnection myConn = new SqlConnection(Connection);

    SqlCommand SelectCommand = new SqlCommand("select * from tar_login where Username ='" + txtUsername.Text + "' and Password='" + txtPassword.Text + "' and Position='" + ddlPosition.Text + "';", myConn);

    myConn.Open();

    Sqldatareader myReader = SelectCommand.ExecuteReader();
    myConn.Close();

     if (reader.HasRows)
        {
if (ddlPosition.Text == "Admin")
        {
            Response.Redirect("manager.aspx");
        }
else if (ddlPosition.Text == "Staff")
        {
            Response.Redirect("staff.aspx");
        }
    else
    {
        Label1.ForeColor = System.Drawing.Color.Red;
        Label1.Text = "Incorrect. Please try again";
        myConn.Close();
    }

hi, i tried ur code but i got a squiggly line underneath HasRows. and when i put my cursor over it, i got this error: 'object' does not contain a definition for 'HasRows' and no extension of method 'HasRows' accepting a first argument of type 'object' could be found — Tar7, Aug 31 '14 at 07:05
http://stackoverflow.com/questions/12609959/how-to-check-if-sqldatareader-has-no-rows Check the link for checking datareader has rows or not — Ubiquitous Developers, Sep 01 '14 at 05:05

Input string was not in a correct format c# and asp.net

3 Answers3