Actually, "that" removes the 'seconds [and milliseconds]' part from entered datetime, so "2008-11-10 08:00:30.123" => "2008-11-10 08:00:00". Ugly, I agree.

Hi Mehroz, I'm working on some model limitations and, when I ready to go, I'll post @ CP, for sure. Thanks for your incentive, Rubens

Looking at System.Data.OleDb implementation through Reflector, GetInt32 and GetValue returns values based on column types, so I think both have similar performance. And, if I had to code an IF inside that generic method, I prefer to stick with current ADO.NET implementation About your second thought, I share your feelings. My main point is to define a simple pattern for data fetch, probably in a structure like Entity (get/set/read) >> Data (DAL/.executeXXX) >> Business (work with loaded data) >> and so on. Thank you for your comments, I really appreciate them. Rubens

Sorry Michal, here you go. ty

Hi there, I'm looking for some advise for a generic data fetch pattern for IDataReader I'm working on, as follow: // main load using(GenericDataReader reader = new GenericDataReader(cm.ExecuteReader())) { while (reader.Read()) { orders.Add(reader.Get<Order>()); // "GetList" pattern //return new Order(reader); // "Get" pattern } } // generic reader; interface implementation removed public class GenericDataReader : IDataReader { // ... \\ public T Get<T>(string name) { int i = _dataReader.GetOrdinal(name); if (_dataReader.IsDBNull(i)) return default(T); else return (T)_dataReader.GetValue(i); } public T Get<T>() where T : ILoadable, new() { T entity = new T(); entity.Load(this, false); return entity; } } // All business objects must implements this interface public interface ILoadable { void Load(GenericDataReader reader, bool deep); } // Sample business object class Order : ILoadable { int id; Customer customer; // Note DateTime orderDate; DateTime requiredDate; DateTime? shippedDate; List<OrderDetail> orderDetails; public Order(){ } public Order(GenericDataReader reader) { Load(reader, true); } #region ILoadable Members public void Load(GenericDataReader reader, bool deep) { id = reader.Get<int>("OrderID"); customer = reader.Get<Customer>(); // Note orderDate = reader.Get<DateTime>("OrderDate"); requiredDate = reader.Get<DateTime>("OrderRequiredDate"); shippedDate = reader.Get<DateTime?>("OrderShippedDate"); if (deep && reader.NextResult()) { orderDetails = new List<OrderDetail>(); while (reader.Read()) { orderDetails.Add(reader.Get<OrderDetail>()); } } } #endregion } What do you think? Are there any major drawback with this model I'm missing? Are there any more clever way to do that? I really appreciate your time reading this. Thanks in advance, Rubens

Hi there, I'm looking for some advise for a generic data fetch pattern for IDataReader I'm working on, as follow:

// main load
using(GenericDataReader reader = new GenericDataReader(cm.ExecuteReader()))
{
while (reader.Read())
{
orders.Add(reader.Get<Order>()); // "GetList" pattern
//return new Order(reader); // "Get" pattern
}
}

// generic reader; interface implementation removed
public class GenericDataReader : IDataReader
{
// ... \\

public T Get<T>(string name)
{
    int i = \_dataReader.GetOrdinal(name);
    if (\_dataReader.IsDBNull(i))
        return default(T);
    else
        return (T)\_dataReader.GetValue(i);
}

public T Get<T>() where T : ILoadable, new()
{
    T entity = new T();
    entity.Load(this, false);
    return entity;
}

}

// All business objects must implements this interface
public interface ILoadable
{
void Load(GenericDataReader reader, bool deep);
}

// Sample business object
class Order : ILoadable
{
int id;
Customer customer; // Note
DateTime orderDate;
DateTime requiredDate;
DateTime? shippedDate;
List<OrderDetail> orderDetails;

public Order(){ }

public Order(GenericDataReader reader)
{
    Load(reader, true);
}

#region ILoadable Members

public void Load(GenericDataReader reader, bool deep)
{
    id = reader.Get<int>("OrderID");
    customer = reader.Get<Customer>(); // Note
    orderDate = reader.Get<DateTime>("OrderDate");
    requiredDate = reader.Get<DateTime>("OrderRequiredDate");
    shippedDate = reader.Get<DateTime?>("OrderShippedDate");
    if (deep && reader.NextResult())
    {
        orderDetails = new List<OrderDetail>();
        while (reader.Read())
        {
            orderDetails.Add(reader.Get<OrderDetail>());
        }
    }
}

#endregion

}

What do you think? Are there any major drawback with this model I'm missing? Are there any more clever way to do that? I really appreciate your time reading this. As long we come to a conclusion I'll write an article for CP with that we learned about it. TIA, Rubens EDIT: Added formatting

modified on Thursday, March 20, 2008 6:44 AM