1 public void test()
 2 {
 3     //OK
 4     string strConnectBySid = "Data Source =(DESCRIPTION =(ADDRESS=(PROTOCOL=TCP)(HOST =" + OracleConnectInfo.strDbIPOrHostName
 5         + ")(PORT=" + OracleConnectInfo.iDbPort + "))(CONNECT_DATA=(SID =" + OracleConnectInfo.strDbSID
 6         + "))); User Id = " + OracleConnectInfo.strDbUser + "; Password=" + OracleConnectInfo.strDbPassword + ";";
 7 
 8     using (OracleConnection conn = new OracleConnection(strConnectBySid))
 9     {
10         conn.Open();
11         string sql = "select 1 from dual";
12         //string sql = "select cname from tm_user where id = 21728";
13 
14         using (OracleCommand cmd = new OracleCommand(sql, conn))
15         {
16             object o = cmd.ExecuteScalar();
17             System.Console.WriteLine("ExecuteScalar:" + o);
18         }
19         conn.Close();
20     }
21 }