I've multiple stand out files that we open as datatable I wish to merge all of this datatables single DataTable insinternet.

eg, Apr09.xls,May09.xls,Jun09.xls

All have dataas follows

Apr09.xls

EMPCODE,PresentDays
0001   ,30
0002   ,21

May09.xls

EMPCODE,PresentDays
0001   ,25
0002   ,30

New datatable is going to be the following

EMPCODE,PresentDays
0001   ,30
0002   ,21
0001   ,25
0002   ,30

How you can create this.

Datatable.Merge may be used the following

For Each fileName As String In Directory.GetFiles("C:\\TEMP\\", "*.xls")
    Dim connectionString As String = String.Format("Provider=Microsoft.Jet.OLEDB.4.0; data source={0}; Extended Properties=""Excel 8.0;HDR=NO;IMEX=1;""", fileName)
    Dim adapter As New OleDbDataAdapter("SELECT * FROM [Sheet1$]", connectionString)
    Dim ds As New DataSet
    adapter.Fill(ds, "anyNameHere")
    Dim TempTable As DataTable
    TempTable = ds.Tables.Item("anyNameHere")
    table1.Merge(TempTable)
    MsgBox(fileName)
Next
DataGridView1.DataSource = table1
MsgBox(table1.Rows.Count)