If you get DBNull values when reading an excel fil through Microsoft.Jet.OLEDB provider, although cells contain values
there is a simple trick: add a parameter "IMEX=1" to the connection string, to force the cells to be read as text ...
Provider=Microsoft.Jet.OLEDB.4.0;Data Source=FileName.xls;Extended Properties="Excel 8.0;IMEX=1"
0c3be6f7-d0cc-4568-8cb1-697decb942b7|1|5.0