I can link oracle 12c Database with unity3d,but cannot query any data,why?

I can link oracle 12c Database with unity3d,but cannot query any data.The same codes in other vs2015 program whitout unity3d are normal execution.I use the System.Data.OracleClient.dll.Any help would be very appreciated, thanks.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using System;
 using System.Data;
 using System.Data.OracleClient;
 using UnityEngine.UI;
 
 public class LinkOracle : MonoBehaviour {
         public static OracleConnection conn;
     static string connectStr = "User ID=system;Password=Zhutong66;Data Source=MONITOR_ORCL;";
     
     String Query="select Assessment_Status from Record_Info_TB where Start_Date>=(sysdate-1/3600/24) and regexp_like(Assessment_Status,'^*.DANGEROUS$')";
 void Start () {
 
                 conn = new OracleConnection(connectStr);
                 string LinkStatus = conn.State.ToString();
                 Console.WriteLine(LinkStatus);
                 conn.Open();
                 string LinkStatus = conn.State.ToString();
                 Debug.Log(LinkStatus);
                  this.InvokeRepeating("Estimate",2.0f,0.5f);}
  private void Estimate(){
 
         OracleCommand ocd = new OracleCommand ();
         ocd.Connection = conn;
         ocd.CommandText = Query;
         ocd.CommandType = System.Data.CommandType.Text;
         //OracleDataReader odr = new OracleDataReader ();
         OracleDataReader odr = ocd.ExecuteReader();
         while(odr.Read()){
          Debug.Log("many data");
            }
      }
 }