Unspecified error when opening excel DB connection from .NET C#

I use the same provider in classic asp on the same machine so I know it's there. I will try connecting with the dataset though. Thanks

When attempting to add the connection to the dataset, I get an "Unrecognized database format" error. The excel filename will not always be the same so connecting with a dataset is not my first choice anyway.

in line 6 you are removing extension
try using filename with extension
string sheetName = Path.GetFileNameWithoutExtension(saveFile);    

use
 Path.GetFileName

oh i missed info
u fetching sheetname :D
still check your conn string
"HDR=Yes;" indicates that the first row contains columnnames, not data
"IMEX=1;" tells the driver to always read "intermixed" data columns as text

check weather you want these

Yes... I want those 2 parameters there. My spreadsheet has column names and I also want to read all of the data as text.

hi
can you provide the stack trace also use try catch to get the exact error msg
otherwise your code is fine

The error that I get with try catch is still "Unspecified error".
The stacktrace is
at System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection) at System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.OleDb.OleDbConnection.Open() at Admin_Batches_UploadFile.DisplayFileContents(HttpPostedFile file) in c:\Inetpub\wwwroot\PureCM\DriverPay\Admin\Batches\UploadFile.aspx.cs:line 119

it seems your uploaded file still is in process

check weather excel object is running in background if it is trying killing it
u can use the following code
 

KillAllInstancesOfProcess("EXCEL");
 
public void KillAllInstancesOfProcess(string strProcessName)
       {
            Process[] objProcess = Process.GetProcessesByName(strProcessName);
 
 
            if (objProcess != null && objProcess.Length > 0)
                foreach (Process oProcess in objProcess)
                {
                    DateTime dtProcessStartTime = oProcess.StartTime;
                    DateTime dtCurrentTime = DateTime.Now;
 
                    TimeSpan objTimeSpan = dtCurrentTime.Subtract(dtProcessStartTime);
                    if (objTimeSpan.Seconds < 3)
                    {
                        System.Threading.Thread.Sleep((3 - objTimeSpan.Seconds) * 1000);
                    }
 
                    oProcess.Kill();
                }
        }

                                              

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rakeshjaimini - I hope I gave you the information you were asking for. I am very new to .NET... thanks for all the help so far.

Through doing some research online, I have found that OleDb Providers suppress raised errors so I switched an Odbc Driver connection. I am still getting an error, but it seems more useful than "Unspecified error".

Here are the errors:
ERROR [HY000] [Microsoft][ODBC Excel Driver]General error Unable to open registry key 'Temporary (volatile) Jet DSN for process 0x384 Thread 0x340 DBC 0x3da9f4 Excel'.
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute Extended Properties
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute HDR
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute IMEX
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute Extended Properties
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute HDR
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute IMEX
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute Extended Properties
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute HDR
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute IMEX
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute Extended Properties
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute HDR
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute IMEX
ERROR [IM006] [Microsoft][ODBC Driver Manager] Driver's SQLSetConnectAttr failed
ERROR [HY000] [Microsoft][ODBC Excel Driver]General error Unable to open registry key 'Temporary (volatile) Jet DSN for process 0x384 Thread 0x340 DBC 0x3da9f4 Excel'.
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute Extended Properties
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute HDR
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute IMEX
ERROR [HY000] [Microsoft][ODBC Excel Driver] Disk or network error.
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute Extended Properties
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute HDR
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute IMEX
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute Extended Properties
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute HDR
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute IMEX
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute Extended Properties
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute HDR
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute IMEX
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute Extended Properties
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute HDR
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute IMEX
ERROR [HY000] [Microsoft][ODBC Excel Driver]General error Unable to open registry key 'Temporary (volatile) Jet DSN for process 0x384 Thread 0x340 DBC 0x3da9f4 Excel'.
ERROR [HY000] [Microsoft][ODBC Excel Driver]General error Unable to open registry key 'Temporary (volatile) Jet DSN for process 0x384 Thread 0x340 DBC 0x3da9f4 Excel'.
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute Extended Properties
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute HDR
ERROR [01S00] [Microsoft][ODBC Excel Driver]Invalid connection string attribute IMEX
ERROR [HY000] [Microsoft][ODBC Excel Driver] Disk or network error.

Stack Trace:
"   at System.Data.Odbc.OdbcConnection.HandleError(OdbcHandle hrHandle, RetCode retcode)\r\n   at System.Data.Odbc.OdbcConnectionHandle..ctor(OdbcConnection connection, OdbcConnectionString constr, OdbcEnvironmentHandle environmentHandle)\r\n   at System.Data.Odbc.OdbcConnectionOpen..ctor(OdbcConnection outerConnection, OdbcConnectionString connectionOptions)\r\n   at System.Data.Odbc.OdbcConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject)\r\n   at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup)\r\n   at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)\r\n   at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)\r\n   at System.Data.Odbc.OdbcConnection.Open()\r\n   at Admin_Batches_UploadFile.DisplayFileContents(HttpPostedFile file) in c:\\Inetpub\\wwwroot\\PureCM\\DriverPay\\Admin\\Batches\\UploadFile.aspx.cs:line 146\r\n   at Admin_Batches_UploadFile.UploadButton_Click(Object sender, EventArgs e) in c:\\Inetpub\\wwwroot\\PureCM\\DriverPay\\Admin\\Batches\\UploadFile.aspx.cs:line 66\r\n   at System.Web.UI.WebControls.Button.OnClick(EventArgs e)\r\n   at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)\r\n   at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)\r\n   at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)\r\n   at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)\r\n   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)"

const string connStringTemplate =
    "Driver=Microsoft Excel Driver (*.xls);" +
    "DBQ={0};" +
    "Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1\"";
string sheetName = Path.GetFileNameWithoutExtension(saveFile);
Label2.Text = sheetName;
string select = String.Format("SELECT * FROM [{0}$];", sheetName);
 
string connString = String.Format(connStringTemplate, saveFile);
 
DataSet workbook = new DataSet();
using (OdbcConnection oConn = new OdbcConnection(connString))
{
    try
    {
        oConn.Open();
        DataAdapter oda = new OdbcDataAdapter(select, oConn);
        oda.Fill(workbook);
    }
    catch (Exception ex)
    {
        Label2.Text = "<div class=\"alert\"><br />An error occurred. Could not make connection.<br /><br />The error message that was thrown:<br /><br /><i>" + ex.Message + "<br/><br/>" + ex.StackTrace + "</i></div>";
    }
 
}

                                              

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now dont use
"Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1\""

use following string
Excel ODBC Connection String
Driver={Microsoft Excel Driver (*.xls)};DriverId=790;Dbq=C:\MyExcel.xls;DefaultDir=c:\directory;

From these articles in MSDN, it appears to be permissions problems in your Temp folder:

PRB: Error Message: 0x80004005: General Error Unable to Open Registry Key
http://support.microsoft.com/default.aspx?scid=kb;en-us;295297

FP: Error: Unable to Open Jet Temporary Key When You Attempt to Connect to Database
http://support.microsoft.com/default.aspx?scid=kb;en-us;315456

reference

Microsoft][ODBC Excel Driver]General error Unable to open registry key 'Temporary (volatile) Jet DSN for process
http://www.experts-exchange.com/Web_Development/Web_Languages-Standards/ASP/Q_21100983.html

Thanks... I have a meeting, but I'll try your suggestions as soon as I get back. Thanks for all your help so far.

I just tried the fix suggested on MSDN. I gave full control permissions to the IUSR account to the HKEY_LOCAL_MACHINE\SOFTWARE\ODBC registry key, but I'm still getting the error. I really thought that might have fixed it. It does seem like a permission issue now that you mention it... however, I wonder why I am able to use this same driver from my classic ASP code on the same machine. Is there another user that .NET uses to access the registry?

This is driving me up the wall! I also tried giving the ASP.Net machine account permission to that registry key... still the same error.

I tried adding the connection via a dataset again. I had neglected to put the Extended Properties in the last time. When I had all the parameters correct, I got this error: "could not find installable isam"

now i think we are moving in right direction

this is a known issue and its solution can be found at

http://support.microsoft.com/kb/209805

http://bytes.com/topic/asp-net/answers/307292-error-message-could-not-find-installable-isam

http://www.experts-exchange.com/Programming/Languages/Visual_Basic/VB_DB/Q_21341464.html

I should have mentioned that I tried that and it didn't work. I registered the dll for excel and for Microsoft Jet 3.x. I'm still getting the error: "could not find installable isam"

Ok... here's the latest. The excel file that I am connecting to was created from a classic asp page using html so I needed to change the extended properties to reflect this. I am now able to connect to the file using an oledbconnection with a dataset by changing one parameter:
Extended Properties=HTML Import... instead of Extended Properties=Excel 8.0

However, I still get "Unspecified error" when using the same connection string in C#. I would love to just use the Dataset connection, however the excel file will be uploaded to the server and will always be different. I suppose I could save over the same file on every upload and use the same filename every time. This is the route I will take if no one has any answers here.

now i got it
as your file is of html type saved with xls extension the problem is coming
so try save your file using excel object
then it will be pure excel documnet
then use it for connection

if you need help in saving file using excel object then do ask me

Yes, I hadn't realized that was an import detail since it didn't matter in classic ASP. I do need help saving the file using the excel object. Thanks for offering. Do I need to have office installed on the web server to do this? I don't think we do currently and I doubt that my company will allow it.

yes you will need office on the server

one more thing you can do

create an empty template excel file and then when you are saving the content
instead of saving html data save using DOM (above method you are using for reading data )
then read the content whenever you require
the main benefit will be
1. the file will be pure excel file and hence there will be no problem in reading
2. you wont need office on the server
3. also your task will be completed

i know this will increase your work but everything will work without installing office
and if you can arrange office then i will tell you the way of using Excel object

I attempted to connect to a pure excel file just so I would be able continue my work and I am getting the same "Unspecified error" on opening the connection.  I have come to realize that this is an environment issue with the dev box I'm working on. A co-worker ran the same script on their machine and it connects to the file with no errors. I am also having problems connecting to a "normal" excel file on this machine so I have a different issue than I originally thought.

I moved to another dev machine and everything is working as it should now. It looks like reinstalling windows is the answer after all. Thanks for your help rakesh. You really helped me to figure out the problem by process of elimination.