C#: Read and Query Data from Excel File

The following code will show a simple example which reads and queries data in the file.

       protected static String connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;" +
                                  "Data Source=" + "C:\\sharedsupport.xls;" +
                                  "Extended Properties=Excel 8.0;";
        //

        //"Select * from [" + DropDownList1.SelectedValue + "$A5:I" + rowNum + "]"
        //

        public Product findValue(Product item, DataTable table, ArrayList fieldList)
        {
            var query = from r in table.AsEnumerable()
                        where r.Field<String>("Product Part Number") == item.name
                        select new{family = r.Field<Object>(fieldList[0].ToString())};

            foreach (var q in query){
                retun new Product() {family = q.family.ToString()};
            }
            return item;
        }
        //

        public DataTable getQueryTable(String cmd)
        {
            OleDbConnection conn = new OleDbConnection(connectionString);
            conn.Open();

            OleDbCommand dbCommand = new OleDbCommand(cmd, conn);
            OleDbDataAdapter adapter = new OleDbDataAdapter();
            adapter.SelectCommand = dbCommand;
            DataSet dataSet = new DataSet();
            adapter.Fill(dataSet);

            conn.Close();
            return dataSet.Tables[0];
        }