"Could Not find Installable ISAM" C# Exception after reading xls file

Question

We are reading xls file which is getting updated regularly from external links. We have loop which read the same file after some interval of 200ms. After reading file for 1000+ time, we are getting Error

"The Microsoft Jet database engine cannot open the file ''. It is already opened exclusively by another user, or you need permission to view its data."

Connection string is as follows:

Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\FeedFiles\TESTING1.xls;Extended Properties="Excel 8.0;HDR=YES;IMEX=1;Importmixedtypes=text;typeguessrows=0;"

And after some time, it start giving "Could not find Installable ISAM".

Code as follows:

String xlsConnString = String.Format(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=""Excel 8.0;HDR=YES;IMEX=1;Importmixedtypes=text;typeguessrows=0;""", feedFiles.FullName);

OleDbDataAdapter dataAdapter = new OleDbDataAdapter(xlsQuery, xlsConnString);
while (true)
{
    try
    {
        //Exception handling if not able to read xls file.
        DataSet dataSet = new DataSet();
        dataAdapter.Fill(dataSet);
        String fileName = dirstr + "Temp-";
        System.IO.StreamWriter file = new System.IO.StreamWriter(fileName + ".tmp");

        file.WriteLine(dataSet.GetXml());
        file.Close();

        try
        {
            File.Replace(fileName + ".tmp", dirstr + "Temp-" + filecount.ToString() + ".xml", null);
        }
        catch (Exception ex)
        {
            try
            {
                File.Move(fileName + ".tmp", dirstr + "Temp-" + filecount.ToString() + ".xml");
            }
            catch
            {
                Thread.Sleep(xlsThreadSleep);
            }
        }

        filecount++;
        if (filecount > maxFileCnt)
        {
            filecount = 0;
        }
        dataSet.Clear();
        dataSet = null;

        Thread.Sleep(xlsThreadSleep);
    }
    catch (Exception ex)
    {
        txtlog.BeginInvoke(new DelegateForTxtLog(functionFortxtLog), "Exception occured > " + ex.Message);
        feedFileIndex++;

        if (feedFileIndex == feedFiles.Length)
        {
            feedFileIndex = 0;
        }
        dataAdapter.Dispose();
        dataAdapter = null;

        Thread.Sleep(xlsThreadSleep * 20);

        xlsConnString = String.Format(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=""Excel 8.0;HDR=YES;IMEX=1;Importmixedtypes=text;typeguessrows=0;""", feedFiles[feedFileIndex].FullName);
        txtlog.BeginInvoke(new DelegateForTxtLog(functionFortxtLog), "Trying connecting with connection string > " + xlsConnString);

        dataAdapter = new OleDbDataAdapter(xlsQuery, xlsConnString);
        txtlog.BeginInvoke(new DelegateForTxtLog(functionFortxtLog), "Now reading file > " + feedFiles[feedFileIndex].FullName);
    }
}

1. This code (without *txtlog* related lines) ran just fine on my machine for over than 1000 times. So the trouble might relate to the data inside your xls file 2. Where the exception raises ? Which row ? 3. did you tried to add *;Mode=Share Exclusive;* to the connection string ? — itsho, Aug 20 '13 at 07:04

score 1 · Answer 1 · answered Jun 11 '12 at 05:00

1

Connection string is not formatted properly. Try this:

String xlsConnString = String.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=
             {0};Extended Properties=\"Excel 8.0;HDR=YES;
             IMEX=1;Importmixedtypes=text;typeguessrows=0;\"", feedFiles.FullName);

answered Jun 11 '12 at 05:00

KV Prajapati

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But I am able to read file for almost 1000+ times with the same connection string and get above error when reading recursively. – rajeshemailto Jun 11 '12 at 06:57
Tried but same error. Also, one more point.. This complete code is written within the thread. – rajeshemailto Jun 11 '12 at 07:29

"Could Not find Installable ISAM" C# Exception after reading xls file

1 Answers1