Convert Excel Range to ADO.NET DataSet or DataTable, etc

Question

I have an Excel spreadsheet that will sit out on a network share drive. It needs to be accessed by my Winforms C# 3.0 application (many users could be using the app and hit

Answer 1

I made method which can take alredy filtered data from Excel Taking filtered data in Range format

        Worksheet sheet = null;
        sheet = (Worksheet)context.cDocumentExcel.Sheets[requiredSheetName];

        DataTable dt = new DataTable();
        sheet.Activate();
        sheet.UsedRange.Select();
        List<Range> ranges = new List<Range>();
        Range usedrange = sheet.UsedRange;

        foreach (var oneRange in usedrange.SpecialCells(XlCellType.xlCellTypeVisible))
        {
            ranges.Add(oneRange);
        }


        dt = (_makeTableFromRange(ranges));

Converting from Range to DataTable

 private static DataTable _makeTableFromRange(List<Range> ranges)
    {
        var table = new DataTable();


        foreach (var range in ranges)
        {
            while (table.Columns.Count < range.Column)
            {
                table.Columns.Add();
            }

            while (table.Rows.Count < range.Row)
            {
                table.Rows.Add();
            }

            table.Rows[range.Row - 1][range.Column - 1] = range.Value2;
        }


        //clean from empty rows
        var filteredRows = table.Rows.Cast<DataRow>().
                        Where(row => !row.ItemArray.All(field => field is System.DBNull ||
                                                                 string.Compare((field as string).Trim(), string.Empty) ==
                                                                 0));
        table = filteredRows.CopyToDataTable();
        return table;
    }

Answer 2

This method does not work well when the same column in the excel spread sheet contains both text and numbers. For instance, if Range("A3")=Hello and Range("A7")=5 then it reads only Hello and the value for Range("A7") is DBNULL

private void Form1_Load(object sender, EventArgs e)
{   
   try
   {        
        DataTable sheetTable = loadSingleSheet(@"C:\excelFile.xls", "Sheet1$");
        dataGridView1.DataSource = sheetTable;
   }
   catch (Exception Ex)
   {
        MessageBox.Show(Ex.Message, "");
   }  
}        

private OleDbConnection returnConnection(string fileName)
{
    return new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileName + "; Jet OLEDB:Engine Type=5;Extended Properties=\"Excel 8.0;\"");
}

private DataTable loadSingleSheet(string fileName, string sheetName)
{           
    DataTable sheetData = new DataTable();
    using (OleDbConnection conn = this.returnConnection(fileName))
    {
       conn.Open();
       // retrieve the data using data adapter
       OleDbDataAdapter sheetAdapter = new OleDbDataAdapter("select * from [" + sheetName + "]", conn);
        sheetAdapter.Fill(sheetData);
    }                        
    return sheetData;

Answer 3

I don't know about a built-in function, but it shouldn't be difficult to write it yourself. Pseudocode:

DataTable MakeTableFromRange(Range range)
{
   table = new DataTable
   for every column in range
   {
      add new column to table
   }
   for every row in range
   {
      add new datarow to table
      for every column in range
      {
         table.cells[column, row].value = range[column, row].value
      }
   }
   return table
}

Answer 4

I don't know what type of data you have.But for an excel data like shown in this link http://www.freeimagehosting.net/image.php?f8d4ef4173.png, you can use the following code to load into data table.

    private void Form1_Load(object sender, EventArgs e)
    {   
       try
       {        
            DataTable sheetTable = loadSingleSheet(@"C:\excelFile.xls", "Sheet1$");
            dataGridView1.DataSource = sheetTable;
       }
       catch (Exception Ex)
       {
            MessageBox.Show(Ex.Message, "");
       }  
    }        

    private OleDbConnection returnConnection(string fileName)
    {
        return new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileName + "; Jet OLEDB:Engine Type=5;Extended Properties=\"Excel 8.0;\"");
    }

    private DataTable loadSingleSheet(string fileName, string sheetName)
    {           
        DataTable sheetData = new DataTable();
        using (OleDbConnection conn = this.returnConnection(fileName))
        {
           conn.Open();
           // retrieve the data using data adapter
           OleDbDataAdapter sheetAdapter = new OleDbDataAdapter("select * from [" + sheetName + "]", conn);
            sheetAdapter.Fill(sheetData);
        }                        
        return sheetData;
    }

Answer 5

It's worth to take a look at NPOI when it comes to read/write Excel 2003 XLS files. NPOI is a life saver.

I think you'll have to iterate your range and create DataRows to put in your DataTable.

This question on StackOverflow provides more resources:

Create Excel (.XLS and .XLSX) file from C#