Index (zero based) must be greater than or equal to zero?

Question

This is the error I get:

Index (zero based) must be greater than or equal to zero and less than the size of the argument list

This is the code:

<%@ Page Language="C#"%>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.OleDb" %>


<!DOCTYPE html>

<script runat="server">



public void Page_Load()
{
    string a, c;
    a = Request.Form["username"];

    string connstring = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + Server.MapPath("SQL/Site_Database.accdb");
    string sqlstring = string.Format("select * from iUsers_Table where (iusername='{0}')", a);
    OleDbDataAdapter da = new OleDbDataAdapter(sqlstring, connstring);
    DataSet ds = new DataSet();
    da.Fill(ds);


    c = Request.Form["mail"];

    string connstring1 = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + Server.MapPath("SQL/Site_Database.accdb");
    string sqlstring1 = string.Format("select * from iUsers_Table where (imail='{0}')", c);
    OleDbDataAdapter da1 = new OleDbDataAdapter(sqlstring1, connstring1);
    DataSet ds1 = new DataSet();
    da1.Fill(ds1);

    if ((ds.Tables[0].Rows.Count == 0) || (ds1.Tables[0].Rows.Count == 0))
    {

        string b, d, e, f, g, h;

        b = Request.Form["password"];
        d = Request.Form["gender"];
        e = Request.Form["age"];
        f = Request.Form["prob"];
        g = Request.Form["prob_val"];
        h = Request.Form["fitness"];

        sqlstring = string.Format("insert into iUsers_Table (iusername,ipassword,imail,igender,iage,iproblem,iproblem_value,ifitness) values('{0}','{1}','{2}','{3}',{4},'{5}',{6},'{7}')", a, b, c, d, e, f, g, h);
        OleDbConnection conn = new OleDbConnection(connstring);
        OleDbCommand cmd = new OleDbCommand(sqlstring, conn);
        conn.Open();
        cmd.ExecuteNonQuery();
        conn.Close();

        Session["connect_status"] = "connected";
        Response.Redirect("My_Plan.aspx");

    }

    else

    {
        if ((ds.Tables[0].Rows.Count) > 0)
        {
            Session["subscribed"] = "exist";

            if ((ds1.Tables[0].Rows.Count) > 0)
            {
                Session["mail"] = "exist";
                Response.Redirect("index.aspx");
            }

            Response.Redirect("index.aspx");
        }
    }
}
</script>

I created a sign up form and this code is used to insert the data into the database and check also for existing equal mail and username values.

Anyone know why this is happening?

Thank you!

Where do you get that error? You've posted 73 lines of code, and left us to guess where the problem is. Ideally, reduce it to a minimal reproducible example. — Jon Skeet
Also, you should read up on parameterized SQL immediately to avoid the SQL injection vulnerability that your code currently has (in multiple places). — Jon Skeet
Are you sure ds.Tables and ds1.Tables have at least one value? — Arturo Menchaca
Try adding if (ds.Tables.Count > 0 && ds1.Tables.Count > 0) before if ((ds.Tables[0].Rows.Count == 0) || ... — Arturo Menchaca
@CommandoMan - Jon Skeet's first question is still most important. What line in your code is throwing that error? — Adam V

Quantic Quantic · Accepted Answer · 2016-03-16T14:30:21

string sqlstring1 = string.Format("select * from iUsers_Table where (imail='{2}')", c);

{2} doesn't exist as there is only one argument in the string.Format(). Note that I googled it which led me to here (hint hint).

So change it to this: string sqlstring1 = string.Format("select * from iUsers_Table where (imail='{0}')", c);

and try again.

Index (zero based) must be greater than or equal to zero?

4 Answers