How Do I Compare With Database Value

string ppo_no = "Set ppo_no value"; //E.G. 1138
            string billDate = "Set billdate"; //E.G. 4/6/2014

            string DeleteStr = "select * from Tablename where ppo_no="+ppo_no+" and convert(varchar,billdate,106)=convert(varchar,"+billDate+",106)"; //You can set date format whatever you want
         
            SqlConnection cn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionstringName"].ConnectionString);
            SqlCommand sql_cmd = new SqlCommand(DeleteStr, cn);
            cn.Open();
            DataTable dtGetData = new DataTable();
            SqlDataAdapter da = new SqlDataAdapter(sql_cmd);
            da.Fill(dtGetData);
            if (dtGetData.Rows.Count > 0)
            {
                //Data already exists.. :)

            }
            else
            { 
                //Data is not exists. :)
            
            }


            cn.Close();
            cn.Dispose();
            sql_cmd.Dispose();