public DataTable GetOpticalInfo(string begindate, string enddate, string prefromid)

        {

            const string connStr = @"Data Source=127.0.0.1;DataBase=master;User ID=sa;PWD=123"

            var conn = new SqlConnection(connStr);

            var ds = new DataSet();

            var dt = new DataTable();

            var strsql = "select * from ##临时表";

            strsql += " where 1=1";

            if (begindate != null && enddate != null)

                strsql += " and 入库时间 between '" + begindate + "' and '" + enddate + "'";

                   strsql += " order by id desc";

            try

            {

                conn.Open();

                var cmd = new SqlCommand(strsql, conn);

                SqlDataAdapter adp = new SqlDataAdapter(cmd);

                adp.Fill(ds, "table1");

            }

            catch (Exception ex)

            {

                throw ex;

            }

            finally

            {

                conn.Close();

            }

            dt = ds.Tables[0];

            return dt;

        }