System.InvalidOperationException: Invalid attempt to read when no data is present.

EDN Admin · Oct 30, 2012

Hello everyone,
I kind of new to C# object oriented programming and I recently started working for a company that their previous IT guy had wrote some code for a module in the website. It had an error when he left but he did not document it so I have no idea what it could
be

. So if anyone could please help me with this error that would be great.
Thank you in advance.

 
Source Error:
<table bgcolor="#ffffcc" width="100%
<tbody>
<tr>
<td>

Code:

<pre> Line 31:         // rows represent privileges (AddModify, Delete, View)
Line 32:         // stored in database as a bit (0 or 1); boolean value; user has right or doesnt
<span style="color:red Line 33:         userpriv[0, 0] = Convert.ToBoolean(reader[0]);
Line 34:         //userpriv[0, 1] = Convert.ToBoolean(reader[1]);
Line 35:         //userpriv[0, 2] = Convert.ToBoolean(reader[2]);

[/code]</td>
</tr>
</tbody>
</table>

The error is located in the masters page and the whole module seems to have been created from Visual Studio 2010 also it is an ASP.NET website written in C# with a SQL Server 2008 backend.
Rest of the pages code:
<%@ Master Language="C#" %> 
<?xml version="1.0" encoding="utf-8"?> 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" 
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd 
 
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en 
<head runat="server 
<title>Concepts West Training Database</title> 
</head> 
<body alink="blue" vlink="blue" link="blue" bgcolor="white 
<table cellpadding="30px" cellspacing="0" align="left" cols="2 
<tr valign="top 
<td align="left 
 
 
<% 
// get username stored in session variable and look it up in [TR_Privileges] table 
string username = Session["uname"].ToString().Trim(); 
string usergroup = Session["ugroup"].ToString().Trim().ToUpper(); 
 
System.Data.SqlClient.SqlConnection conn = new System.Data.SqlClient.SqlConnection(); 
conn.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["CWIS"].ConnectionString; 
conn.Open(); 
string commandString = "SELECT [Employee_AddModify], [Employee_Delete], [Employee_View], [ECC_AddModify], [ECC_Delete], [ECC_View], [Procedures_AddModify], [Procedures_Delete], [Procedures_View], [Revs_AddModify], [Revs_Delete], [Revs_View],
[Reqs_AddModify], [Reqs_Delete], [Reqs_View], [Sessions_AddModify], [Sessions_Delete], [Sessions_View] FROM dbo.[TR_Privileges] WHERE [Username] = " + username + ";"; 
System.Data.SqlClient.SqlCommand command = new System.Data.SqlClient.SqlCommand(commandString, conn); 
System.Data.SqlClient.SqlDataReader reader = command.ExecuteReader(); 
reader.Read(); 
 
bool[,] userpriv = new bool[6, 3]; // array to hold result of query 
// array is 6x3; 6 columns and 3 rows; columns represent categories (Employee, ECC, Procedures, Revs, Reqs, Sessions) 
// rows represent privileges (AddModify, Delete, View) 
// stored in database as a bit (0 or 1); boolean value; user has right or doesnt 
userpriv[0, 0] = Convert.ToBoolean(reader[0]); 
//userpriv[0, 1] = Convert.ToBoolean(reader[1]); 
//userpriv[0, 2] = Convert.ToBoolean(reader[2]); 
//userpriv[1, 0] = Convert.ToBoolean(reader[3]); 
//userpriv[1, 1] = Convert.ToBoolean(reader[4]); 
//userpriv[1, 2] = Convert.ToBoolean(reader[5]); 
//userpriv[2, 0] = Convert.ToBoolean(reader[6]); 
//userpriv[2, 1] = Convert.ToBoolean(reader[7]); 
//userpriv[2, 2] = Convert.ToBoolean(reader[8]); 
//userpriv[3, 0] = Convert.ToBoolean(reader[9]); 
//userpriv[3, 1] = Convert.ToBoolean(reader[10]); 
//userpriv[3, 2] = Convert.ToBoolean(reader[11]); 
//userpriv[4, 0] = Convert.ToBoolean(reader[12]); 
//userpriv[4, 1] = Convert.ToBoolean(reader[13]); 
//userpriv[4, 2] = Convert.ToBoolean(reader[14]); 
//userpriv[5, 0] = Convert.ToBoolean(reader[15]); 
//userpriv[5, 1] = Convert.ToBoolean(reader[16]); 
//userpriv[5, 2] = Convert.ToBoolean(reader[17]); 
 
reader.Close(); 
conn.Close(); 
 
if (usergroup == "ADMIN") 
{ 
string menu; 
menu = "User Privileges"; 
menu += ""; 
menu += "./training_userpriv_view.aspx>View User Rights "; 
menu += "./training_userpriv_modify.aspx>Modify User Rights "; 
menu += ""; 
Response.Write(menu); 
} 
%> 
Employees 
 
./training_addemployee.aspx Add a New Employee 
./training_modifyemployee.aspx Update Employee Info 
./training_viewemployee.aspx View Employees 
./training_deleteemployee.aspx Delete an Employee 
 
Classification Codes 
 
./training_addecc.aspx Add a New ECC 
./training_viewecc.aspx View ECC List 
./training_deleteecc.aspx Delete an ECC 
 
Procedures/Forms/Aids 
 
./training_addprocedures.aspx Add a New Procedure 
./training_modifyprocedures.aspx Update Procedure Info 
./training_viewprocedures.aspx View Procedures 
./training_deleteprocedure.aspx Delete a Procedure 
 
Revs 
 
./training_addrev.aspx Add a New Rev 
./training_modifyrevs.aspx Update Rev Info 
./training_viewrev.aspx View Revs 
./training_deleterev.aspx Delete a Rev 
 
Requirements 
 
./training_setrequirements.aspx Set Requirements 
./training_viewrequirements.aspx View Reqs. By ECC 
./training_viewrequirementsbyprocedure.aspx View Reqs. By Procedure 
Delete a Requirement 
 
Training Sessions 
 
./training_createsession.aspx Create a Session 
Modify a Session 
View Sessions 
Delete a Session 
 
Miscellaneous Reports 
 
</td> 
<td align="center 
 
<asp:ContentPlaceHolder ID="mainContent" runat="server 
</asp:ContentPlaceHolder> 
</td> 
</tr> 
</table> 
</body> 
</html>

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System.InvalidOperationException: Invalid attempt to read when no data is present.

EDN Admin

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