' I suggest you try to create a secondary datatable that transposes rows to
columns and columns to rows and then fill the values in by iterating .

'Pass the function the table to transpose as well as the primary key column
name i.e. InvoiceNumber

call the program like this:

Dim transdt as DataTable

transdt = TransposeDataTable(sometable,"id_firm")

datagrid1.datasource= transdt

Private Function TransposeDataTable(Byval CurrentTable as DataTable,Byval
PrimaryColumnName as String) as DataTable

Dim dt As New DataTable

Dim rows As Integer = 0

'add a column for the table values

Dim dcolvalue As New DataColumn("ColumnName")

With dcolvalue

.DataType = GetType(String)

.MaxLength = 255

End With

dt.Columns.Add(dcolvalue)

'loop through each row and create a column

For Each row As DataRow In CurrentTable.Rows

Dim dcol As New DataColumn(row(PrimaryColumnName).ToString) 'or add the
columnName as PrimaryKey

dt.Columns.Add(dcol)

rows += 1

Next

'iterate all the columns and create rows

For Each col As DataColumn In CurrentTable.Columns

Dim ColRow As DataRow

ColRow = dt.NewRow

ColRow.Item(0) = col.ColumnName

dt.Rows.Add(ColRow)

Next

'Now populate the information by iterating the rows over the columns

For i As Integer = 0 To CurrentTable.Rows.Count - 1

   For k As Integer = 0 To CurrentTable.Columns.Count - 1

       dt.Rows(k)(i + 1) = CurrentTable.Rows(i).Item(k)

   Next

Next

return dt

End Sub