I have a data table . The data table is basically getting populated from excel sheet. And there are many excel sheets. Henceforth, I have written a utility method for accomplishing the same. Now in some of the excel sheets, there are date columns and in some it is not(only text/string).

My function is populating the values properly into the datatable from the excell sheet. But there are many blank rows in the excel sheets some are filled with NULL , some with " ".

So I need to filter those records (which are NULL or " " ) first before further processing.

What I am after is to use a dataview and apply the filter over there.

DataView dv = dataTable.DefaultView;
dv.RowFilter = ColumnName +  " <> ''";

Well by using metedata (GetOleDbSchemaTable(OleDbSchemaGuid.Columns, restrection)) I was able to get the column names from the excel sheet , so getting the column names is not an issue.

But the problem is as I said in some Excel sheet there are date fileds some are not.

So the Filter condition of the Dataview needs to be proper. If I apply the above logic, and if it encounters a Datafield, it is throwing error

Cannot perform '<>' operation on System.DateTime and System.String.

Could you people please help me out?

I need to filter columns(not known at compile time + their data types) which can have NULL and  " " 

I am using C#3.0

Thanks