How do I import data from a particular column in SQL to label in C#?

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SQL-Server-2014

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Hello,

I am trying to fetch data from a table in SQL Server to Label in my Windows Form. It is showing me a null exception error and I am unable to figure out why.

I am getting this error:
System.IndexOutOfRangeException: '@Name' on the following line:
NameLabel.Text = reader["@Name"].ToString();

I am storing it in a string because I am calling the value in another form.

Please help.

What I have tried:

string queryText = @"SELECT Count(*) FROM NewsClip_Login 
                             WHERE Username = @Username AND Password = @Password";

                using (SqlConnection cn = new SqlConnection("Data Source=PRIMO-CHALICE;Initial Catalog=NewsClip;Integrated Security=True"))
                using (SqlCommand cmd = new SqlCommand(queryText, cn))
                {
                    cn.Open();
                    cmd.Parameters.AddWithValue("@Username", UsernameTextBox.Text);
                    cmd.Parameters.AddWithValue("@Password", PasswordTextBox.Text);
                    cmd.Parameters.AddWithValue("@Name", NameLabel.Text);
                    SqlDataReader reader = cmd.ExecuteReader();

                    reader.Read();
                    NameLabel.Text = reader["@Name"].ToString();
                    NameLabelText = NameLabel.Text;
                    reader.Close();

                    int result = (int)cmd.ExecuteScalar();
                    if (result > 0)
                    {
                        this.Hide();
                        NewsClip_Main nc_main = new NewsClip_Main();
                        nc_main.Enabled = true;
                        nc_main.ShowDialog();

                        this.Close();
                    }
                    else
                        MessageBox.Show("User Not Found!");
                    cn.Close();

Posted 10-May-18 1:13am

Primo Chalice

Updated 10-May-18 1:22am

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Wendelius · Answer 1 · 2018-05-10T01:23:00

You don't have a parameter called @name in your SQL statement. Perhaps you wanted to select it like

SELECT Name FROM NewsClip_Login WHERE Username = @Username AND Password = @Password";

If that is what you're trying to do then you refer to the result columns wiuthout @ since that is used for parameters.

Another thing concerning the password. Never ever store the passwords as plain text. They should always be hashed one-way. Have a look at Password Storage: How to do it.[^]

ADDITION
-----------

string queryText = @"SELECT Name FROM NewsClip_Login WHERE Username = @Username AND Password = @Password";

using (SqlConnection cn = new SqlConnection("Data Source=PRIMO-CHALICE;Initial Catalog=NewsClip;Integrated Security=True")) {
   using (SqlCommand cmd = new SqlCommand(queryText, cn))
   {
      cn.Open();
      cmd.Parameters.AddWithValue("@Username", UsernameTextBox.Text);
      cmd.Parameters.AddWithValue("@Password", PasswordTextBox.Text);
      SqlDataReader reader = cmd.ExecuteReader();

      reader.Read();
      NameLabel.Text = reader["Name"].ToString();
      NameLabelText = NameLabel.Text;
      reader.Close();
      ...

Rajat-Indiandotnet · Answer 2 · 2018-05-10T01:19:00

Solution 1

Sorry I didn't realize that your SQL statement not having Name column

SELECT Count(*) FROM NewsClip_Login

You should have columnname if you are using reader for example if you are fetching the value of name then you should have name column in your select statement.

Remove @ from the reader it should be reader ["Name"]

Posted 10-May-18 1:19am

Rajat-Indiandotnet

Updated 10-May-18 2:42am

v2

Comments

Primo Chalice 10-May-18 7:33am

The error is still there.
System.IndexOutOfRangeException: 'Name'