//数据访问层代码如下: 
            //通用数据访问类代码准确无误 
            //查询语句 
            string orclStr = "Select * from produceEnrol where produceEnrolId='001'"; 
            //用于存储值的类 
            ProduceEnrol p = new ProduceEnrol(); 
            //查询数据库 
            using (OracleDataReader odr = OracleDBHelper.ExecuteReader(OracleDBHelper.CONN_STRING, CommandType.Text, orclStr, null)) 
            { 
                //封闭数据 
                if (odr.Read()) 
                { 
                    //数据库中整列都有值,但只能猎取前两列的值 
                    p.ProduceEnrolId = odr[0].ToString();//类中数据类型:String,Oracle中数据类型:Varchar2                    
                    p.ProduceSend.ProduceSendId = odr[1].ToString();//类中数据类型:String,Oracle中数据类型:Varchar2 
                    try 
                    { 
                        p.PlanEnrolCost = (double)odr[2];//类中数据类型:double,Oracle中数据类型:number 
                    } 
                    catch 
                    {                     } 
                } 
            }             //数据库中整列都有值,但只能猎取前两列的值 
            //请问各位大吓是什么原因????????????