Excel “External table is not in the expected forma

Question

I'm trying to read an Excel (xlsx) file using the code shown below. I get an "External table is not in the expected format." error unless I have the file already open in Excel. In other words, I have to open the file in Excel first before I can read if from my C# program. The xlsx file is on a share on our network. How can I read the file without having to open it first? Thanks

string sql = "SELECT * FROM [Sheet1$]";
string excelConnection = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + pathname + ";Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1;\"";

using (OleDbDataAdapter adaptor = new OleDbDataAdapter(sql, excelConnection)) {
    DataSet ds = new DataSet();
    adaptor.Fill(ds);
}

Answer 1

"External table is not in the expected format." typically occurs when trying to use an Excel 2007 file with a connection string that uses: Microsoft.Jet.OLEDB.4.0 and Extended Properties=Excel 8.0

Using the following connection string seems to fix most problems.

public static string path = @"C:\src\RedirectApplication\RedirectApplication\301s.xlsx";
public static string connStr = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path + ";Extended Properties=Excel 12.0;";

Answer 2

I had this same issue(Using the ACE.OLEDB) and what resolved it for me was this link:

http://support.microsoft.com/kb/2459087

The gist of it is that installing multiple office versions and various office sdk's, assemblies, etc. had led to the ACEOleDB.dll reference in the registry pointing to the OFFICE12 folder instead of OFFICE14 in

C:\Program Files\Common Files\Microsoft Shared\OFFICE14\ACEOLEDB.DLL

From the link:

Alternatively, you can modify the registry key changing the dll path to match that of your Access version.

Access 2007 should use OFFICE12, Access 2010 - OFFICE14 and Access 2013 - OFFICE15

(OS: 64bit Office: 64bit) or (OS: 32bit Office: 32bit)

Key: HKCR\CLSID{3BE786A0-0366-4F5C-9434-25CF162E475E}\InprocServer32\

Value Name: (Default)

Value Data: C:\Program Files\Common Files\Microsoft Shared\OFFICE14\ACEOLEDB.DLL

(OS: 64bit Office: 32bit)

Key: HKCR\Wow6432Node\CLSID{3BE786A0-0366-4F5C-9434-25CF162E475E}\InprocServer32\

Value Name: (Default)

Value Data: C:\Program Files (x86)\Common Files\Microsoft Shared\OFFICE14\ACEOLEDB.DLL

Answer 3

I had this problem and changing Extended Properties to HTML Import fixed it as per this post by Marcus Miris:

strCon = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & importedFilePathAndName _
         & ";Extended Properties=""HTML Import;HDR=No;IMEX=1"";"

Answer 4

(I have too low reputation to comment, but this is comment on JoshCaba's entry, using the Ace-engine instead of Jet for Excel 2007)

If you don't have Ace installed/registered on your machine, you can get it at: http://www.microsoft.com/downloads/details.aspx?FamilyID=7554F536-8C28-4598-9B72-EF94E038C891&displaylang=en

It applies for Excel 2010 as well.

Answer 5

I was getting errors with third party and Oledb reading of a XLSX workbook. The issue appears to be a hidden worksheet that causes a error. Unhiding the worksheet enabled the workbook to import.

Answer 6

Ran into the same issue and found this thread. None of the suggestions above helped except for @Smith's comment to the accepted answer on Apr 17 '13.

The background of my issue is close enough to @zhiyazw's - basically trying to set an exported Excel file (SSRS in my case) as the data source in the dtsx package. All I did, after some tinkering around, was renaming the worksheet. It doesn't have to be lowercase as @Smith has suggested.

I suppose ACE OLEDB expects the Excel file to follow a certain XML structure but somehow Reporting Services is not aware of that.