Ado.net利用反射执行SQL得到实体

public Model.orderParent GetTraceIDforID(string orderid)
        {
            string sql = string.Format(" select * from orderParent where Id='{0}'", orderid);
            DataTable dt = new BaseBLL().DataAccess.QueryDataTable(sql);
            if (dt != null && dt.Rows.Count > 0)
            {
                Model.orderParent data = (Model.orderParent)ReflectionHelper.AssignDataSetToModel(dt, (new Model.orderParent()).GetType());
                return data;
            }
            else
            {
                return null;
            }
        }

　　

 public static Object AssignDataSetToModel(System.Data.DataTable dt, Type objectType)
        {
            try
            {
                if (dt.Rows.Count <= 0)
                {
                    return null;
                }
                System.Reflection.PropertyInfo[] pis = objectType.GetProperties();
                Object obj = null;
                if (null != pis)
                {
                    Type[] paramTypes = new Type[0];
                    object[] paramArray = new object[0];
                    obj = objectType.GetConstructor(paramTypes).Invoke(paramArray);
                    foreach (PropertyInfo pi in pis)
                    {
                        if (pi.DeclaringType.Equals(objectType))
                        {
                            int colIndex = getColindex(pi.Name, dt);
                            if (pi.PropertyType.Name == "Char" || pi.PropertyType.Name == "Int32" || pi.PropertyType.Name == "Single" || pi.PropertyType.Name == "Decimal" || pi.PropertyType.Name == "DateTime" || pi.PropertyType.Name == "Boolean")
                            {

                                if (pi.PropertyType.Name == "Int32")
                                    pi.SetValue(obj, dt.Rows[0][colIndex] == DBNull.Value ? 0 : Convert.ToInt32(dt.Rows[0][colIndex]), null);
                                else if (pi.PropertyType.Name == "Single")
                                    pi.SetValue(obj, dt.Rows[0][colIndex] == DBNull.Value ? 0 : Convert.ToSingle(dt.Rows[0][colIndex]), null);
                                else if (pi.PropertyType.Name == "Decimal")
                                    pi.SetValue(obj, dt.Rows[0][colIndex] == DBNull.Value ? 0 : Convert.ToDecimal(dt.Rows[0][colIndex]), null);
                                else if (pi.PropertyType.Name == "DateTime")
                                    pi.SetValue(obj, dt.Rows[0][colIndex] == DBNull.Value ? DateTime.MinValue : Convert.ToDateTime(dt.Rows[0][colIndex]), null);
                                else if (pi.PropertyType.Name == "Boolean")
                                    pi.SetValue(obj, dt.Rows[0][colIndex] == DBNull.Value ? false : Convert.ToBoolean(dt.Rows[0][colIndex]), null);
                                else if (pi.PropertyType.Name == "Char")
                                    pi.SetValue(obj, dt.Rows[0][colIndex] == DBNull.Value ? '0' : Convert.ToChar(dt.Rows[0][colIndex]), null);
                            }
                            else
                                pi.SetValue(obj, dt.Rows[0][colIndex] == DBNull.Value ? "" : dt.Rows[0][colIndex], null);

                        }
                    }
                }
                return obj;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }