How to upload only non-empty rows of Excel spreadsheet using oledb in C#?

Question

I am importing excel sheet to DataTable using oledb connection as below.

private static DataTable UploadExcelSheet(string fileName)
    {
        DataTable uploadDataTable;
        using (OleDbConnection objXConn = new OleDbConnection())
        {
            objXConn.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + fileName +
                                            ";Extended Properties=\"Excel 12.0;IMEX=1\"";

            objXConn.Open();

            OleDbCommand objCommand =
                new OleDbCommand("SELECT * FROM Template$ ", objXConn);
            OleDbDataAdapter objDataAdapter = new OleDbDataAdapter();

            // retrieve the Select command for the Spreadsheet
            objDataAdapter.SelectCommand = objCommand;

            // Create a DataSet
            DataSet objDataSet = new DataSet();

            // Populate the DataSet with the spreadsheet worksheet data
            objDataAdapter.Fill(objDataSet);
            uploadDataTable = objDataSet.Tables[0];
        }

        return uploadDataTable;
    }

Everything is working fine but problem comes when user delete content of few rows before uploading the excel. It reads those empty rows as well along with non empty rows, and saving data in database fails because of business rule violation (mandatory field missing). What I tried is putting where condition in query :

"SELECT * FROM  WHERE  not [CandidateId*] = 0 or not [Firstname*] = '' or not [Lastname] = '' or not [type*] = '' or not [DOB*] =" + DBNull.Value

So it will select only those rows which has data. But I am not able to compare non string field i.e. Date, Integer etc. Which are comming as DBNull when empty. Can any one please suggest the way to do it, I dont want to use DataReader.

Answer 1

Expanding on vc's answer, this will remove all rows that which each of it's columns contain either nothing or white space:

dataTable = dataTable.Rows.Cast<DataRow>().Where(row => !row.ItemArray.All(field => field is System.DBNull || string.Compare((field as string).Trim(), string.Empty) == 0)).CopyToDataTable();