I have an ASP.NET page with a QueryString in the URL of AlbumID (Example: MyPage.aspx?AlbumID=1). I need to write some codebehind in C# on this page that simply gets an average by running a query for the AlbumID in the querystring, and put that result in a Label1 in the ASP.NET front page.
Here is my code:
protected void Page_Load(object sender, EventArgs e)
SqlConnection myConnection = null;
string connString = ConfigurationManager.ConnectionString["ConnectionString"].ConnectionString;
myConnection = new SqlConnection();
myConnection.ConnectionString = connString;
SqlCommand getAverage = new SqlCommand();
getAverage.CommandText = "SELECT AVG(Rating) FROM Ratings WHERE AlbumID = @AlbumID";
getAverage.Connection = myConnection;
SqlDataReader reader = getAverage.ExecuteReader();
string average = (string)reader["avg"];
Label1.Text += average;
// Just for testing.
Label1.Text += ex.ToString();
When I run this, I get the exception "Must declare the scalar variable "@AlbumID". " and I don't know why it isn't reading what is in the querystring.