访问oracle数据库

1。web.config ----appSettings--<add key="LimsConnection" value="data source=yzlims;user id=lims;password = lims"/>
2.  c#代码中
using System.Data.OracleClient;     
public DataTable  GetLimsTimeInSpace(string S_SAMPLE_NAME, string S_SAMPLING_P_N,DateTime startTime, DateTime endTime)
        {
            DataTable dt = new DataTable();
            OracleConnection conn = new System.Data.OracleClient.OracleConnection(System.Configuration.ConfigurationSettings.AppSettings["LimsConnection"]);
            try
            {
                if (conn.State != ConnectionState.Open)
               conn.Open ();
                string strSql = string.Format(@"select  distinct( s_sampled_date)
                                      from (select row_number() over(order by s_sampled_date desc) rn, t.*
                                              from yzlims.xt_table t
                              &