Reading Excel without Excel

I have a VB.NET app which pulls some data out of an Excel file and puts it into XML.

Originally, I read from the Excel file using an OleDB connection but then when we deployed the app to the test server, it gave an error saying that some Jet database components needed to be registered on the server to read from Excel and we're not allowed to register those on the server.

Then, I rewrote it using the Microsoft.Office.Interop Excel components. Apparently, however, that needs to have Excel registered on the server in order to work and we can't install that either.

Is there another way to read data from Excel using VB.NET which doesn't require anything but the .NET Framework on the server the app is running from? It's just a few simple rows of data with no formulas or macros or anything and I just want to grab the data out. It seems to me that this shouldn't be all that complex.

Why can't you install Excel?

As for Oledb, just download the Oledb provider and install it.

using the oledb method with Jet, your target cpu needs to be set to x86

Ya, they're not letting us install anything on the server for byzantian security reasons which don't make anymore sense after they're explained. That means that I can't do the Jet registration on there to use the OleDB and I can't put Excel on there to use the Interop.

Is there any other kind of Excel component which allows reading of the data (no updates or anything are necessary) which is a self-contained thing that can just be shipped with the application in a dll or the like?

Quote:

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Originally Posted by Tom Sawyer

Ya, they're not letting us install anything on the server for byzantian security reasons which don't make anymore sense after they're explained. That means that I can't do the Jet registration on there to use the OleDB and I can't put Excel on there to use the Interop.

Is there any other kind of Excel component which allows reading of the data (no updates or anything are necessary) which is a self-contained thing that can just be shipped with the application in a dll or the like?

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I'm not 100% familiar with this... but I don't think so.

I know that SQL Server Management Studio manipulates Excel files without needing Excel installed. But maybe it installs the providers when installing itself.

*Edit:

I just Googled it and found this. I haven't looked much into it, but maybe you can change the code to your needs.

Is there any way you could convert your Excel file before it gets to the Server? Save it as a .CSV maybe and read it into VB as a text file?

Interesting option Chris. Is there a way to read that excel file back into vb without knowing the file name exactly?

You can read data from MS-Excel 2007 using Open XML SDK but not prior versions.

The following link has a demo solution which shows how to read Excel sheets, ranges and defined names. I will warn you it is not simple but if you truly want to get away from automation and OleDb this is worth it outside of using a third party library such as Aspose cells (which I use).

MSDN http://msdn.microsoft.com/en-us/library/bb448854.aspx
HOW TO http://msdn.microsoft.com/en-us/library/cc850837.aspx
Code bank article http://www.vbforums.com/showthread.php?t=664975

If the Excel file is saved as a .csv and is either the only .csv file in that location or you know a unique part of its name or available meta data (such as date created) then you can read it into VB using thr GetFiles method and If/Secect statements.

Roughly, if the file has a unique feature that you can get a handle on then, yes, you can read it into VB without knowing its name.

I see. Sorry to hijack another's thread for this but how do you capture the date created when the .csv is exported, say, from a web page?

That will be the only thing I could attest to that will be unique in the case I am working with, unfortunately.

Unless you know of a way to make it save to a specific file name using a URL. :P

I'm not sure how you'd capture the date created that way but, if the directory you're using on the server to store the csv in is only used for that purpose (or will not ever contain csv files used for another purpose), surely the csv file you will want will be the newest one?

As for the other option (save using URL) I have no idea. How are you creating and saving the csv now?

Since an Excel file is just a zipped folder you should be able to unzip it & read the sheet1.xml file that is contained within. I've never done it but it seems like it might be easier than some of the other options on the board...

Quote:

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Originally Posted by nbrege

Since an Excel file is just a zipped folder you should be able to unzip it & read the sheet1.xml file that is contained within. I've never done it but it seems like it might be easier than some of the other options on the board...

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You are correct that an Office Excel 2007 file structure can be read as a zip file containing folders and files. Unfortunately, reading and writing to one of these files is not a simple task when compared to using OleDb or early binding automation. What is critical to know before working with these files is that you should be using Microsoft’s Open XML SDK library (my examples), which I mentioned in my reply earlier. Secondly when working with the XML structure and data that if a worksheet or cell value does not exists it will not be stored in the file. For instance using methods to read cells if row 1 has values through say E1 then you will be able to read the values then we move to row 2 where we have values in A2, nothing in B2, values in C2, D2 and E2 that C2 becomes D2 and D2 becomes E2 unless you have a method that indicates the above so that when returning values say into a DataTable to display we get exactly what you expected.

Here are some example of working with Open XML

Get column names from a specific worksheet

Code:

---

    Public Function GetSheetColumnNames( _
        ByVal FileName As String, _
        ByVal RelationshipId As String, _
        ByVal HasHeader As Boolean) As DataTable

        Dim dt As New DataTable()
        If SheetContainsData(FileName, RelationshipId) = ReasonCodes.FailedToOpen Then
            'My.Dialogs.ExceptionDialog("Failed to open sheet because it is open by another process.")
            Return dt
        End If

        Using spreadSheetDocument As SpreadsheetDocument = spreadSheetDocument.Open(FileName, False)
            Dim WorkBookPart As WorkbookPart = spreadSheetDocument.WorkbookPart
            Dim Sheets As IEnumerable(Of Sheet) = spreadSheetDocument.WorkbookPart _
                .Workbook.GetFirstChild(Of Sheets)().Elements(Of Sheet)()
            Dim WorksheetPart As WorksheetPart = CType(spreadSheetDocument.WorkbookPart _
                .GetPartById(RelationshipId), WorksheetPart)
            Dim WorkSheet As Worksheet = WorksheetPart.Worksheet
            Dim SheetData As SheetData = WorkSheet.GetFirstChild(Of SheetData)()
            Dim Rows As IEnumerable(Of Row) = SheetData.Descendants(Of Row)()

            If Rows.Count = 0 Then
                Return dt
            End If

            Dim HeaderIndex As Integer = 1
            Dim UseData As Boolean = True
            If HasHeader Then
                For Each cell As Cell In Rows.ElementAt(0)
                    dt.Columns.Add(TryGetCellValue(spreadSheetDocument, cell, UseData), GetType(System.String))
                    ' NEED Cell index
                Next cell
            Else
                For Each cell As Cell In Rows.ElementAt(0)
                    dt.Columns.Add("Column" & HeaderIndex.ToString, GetType(System.String))
                    HeaderIndex += 1
                Next cell
            End If

        End Using

        Return dt

    End Function

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Code to read a sheet which accounts for cells which are not stored physically in the file as mentioned above. Lastly I should mention that this code targets a specific format within a specific file which may fail with another format which is no different than working with OleDb methods in regards to how extended properties are set up i.e. IMEX, header no header etc.

Code:

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    ''' <summary>
    ''' Open a sheet
    ''' </summary>
    ''' <param name="FileName">Filename containing sheet</param>
    ''' <param name="dt">DataTable to populate</param>
    ''' <param name="Marker">Column count</param>
    ''' <param name="SheetName">Sheet name via RelationshipId</param>
    ''' <remarks></remarks>
    Public Function PopulateSheet( _
        ByVal FileName As String, _
        ByRef dt As DataTable, _
        ByVal Marker As Integer, _
        ByVal SheetName As String) As String


        Using Document = SpreadsheetDocument.Open(FileName, False)
            Dim WorkBookPart = Document.WorkbookPart
            Dim WorkBook = WorkBookPart.Workbook
            Dim Sheets = WorkBook.Descendants(Of Sheet)()
            Dim SheetInfo = (From T In Sheets Where T.Name = SheetName).FirstOrDefault
            Dim WorkSheetPart = CType(WorkBookPart.GetPartById(SheetInfo.Id), WorksheetPart)
            Dim SharedStringPart = WorkBookPart.SharedStringTablePart
            Dim Values = SharedStringPart.SharedStringTable.Elements(Of SharedStringItem)().ToArray()
            Dim Cells = WorkSheetPart.Worksheet.Descendants(Of Cell)()
            Dim ColumnIndex As Integer = 0

            Dim Row As DataRow = Nothing
            Dim UseData As Boolean = False

            For Each cell As Cell In Cells
                ' Gets the column index of the cell with data
                Dim cellColumnIndex As Integer = CInt(Fix(GetColumnIndexFromName(GetColumnName(cell.CellReference))))
                If cellColumnIndex = 0 Then
                    Row = dt.NewRow
                End If
                If ColumnIndex < cellColumnIndex Then
                    Do
                        ColumnIndex += 1
                    Loop While ColumnIndex < cellColumnIndex
                End If

                If cellColumnIndex <= Marker Then
                    Row(cellColumnIndex) = TryGetCellValue(Document, cell, UseData)
                End If

                If Marker = 1 Then
                    If UseData Then
                        dt.Rows.Add(Row)
                    End If
                ElseIf cellColumnIndex >= Marker Then
                    dt.Rows.Add(Row)
                End If

                ColumnIndex += 1

            Next

        End Using

    End Function

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Using Open XML is but one tool in a toolbox and when used for the right reason is great but for the wrong reason can be a mess.

Reading say 20,000 rows by five columns with OleDb is less than five seconds while using standard Open XML SDK it might take 30 to 60 seconds reading in all rows and cells. Of course with optimization this can be faster yet that is more code.