Question

I have just started to learn C# and I’m a little bit confused about DataSet/DataTable/DataGridView.
For now I’m having a simple form where there is DataGridView, listBox, Insert & Delete buttons. When my form loads in listBox I’m getting excel sheet’s list. Then I choose one of the sheets and then it appears on DataGridView (all information I’m writing to DataSet and DataTable). I would like to add or delete columns at runtime. Here is my code for Delete button:

    excelConn = new OleDbConnection();
    excelConn.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source= " + excelFilePath + ";Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1\"";
    DataTable dt = new DataTable();
    OleDbDataAdapter ExcelAdapt = new OleDbDataAdapter("Select * From " + "[" + tableName + "]", excelConn);
    ExcelAdapt.Fill(dt);
    try
    {
      dt.Columns.Remove(colName);
      dt.AcceptChanges();
      var bds = new BindingSource();
      bds.DataSource = dt;
      grid.DataSource = bds;

      MessageBox.Show("Column(s) deleted ");
      excelConn.Close();
      }

      catch (Exception ex)
      {
         MessageBox.Show(ex.Message);
      }

The problem I’m facing is that I can’t save changes made at runtime and even at runtime these changes are temporary. If at runtime I add new column and then I choose another sheet from ListBox these changes disappear.

I found this tutorial but if I understood well it changes database; well in my case it would change excel file (but I want to have original excel file and making changes only in DataSet and DataTable).

Can I make changes only in DataSet/DataTable. If yes, then how?

Answer 1

Here is the exact solution for your problem which does update the data from DataGridView to Excel, I just tested on my machine and it did worked:

http://blogs.msdn.com/b/spike/archive/2008/10/29/how-to-update-an-excel-worksheet-using-dataset-and-the-oledbdataadapter.aspx

[Edit]

For example the following code will remove Row #3 from the DataGridView1 and local copy of your ds however your EXCEL will not be affected.

dataGridView1.Rows.RemoveAt(2);
ds.Tables["[Sheet1$]"].Rows[2].Delete();

Later when you want to save this data to other EXCEL, you can just export to new EXCEL or same EXCEL different [SheetX].