entity frame ewarkはデータベースの変更を調べず、または指定されたフィールドのセットを除外するための共通の方法です。

このうちDataDB Enttiesはデータベース本体の対象となります。コードは以下の通りです。
ダウンロード住所：http://files.cnblogs.com/stone_w/EFDBHelper.zip

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.Data.Objects.DataClasses;
public class EFDBHelper
{

    #region          
    /// <summary>
    ///          
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="entity"></param>
    /// <param name="db"></param>
    /// <param name="updateFiledType"></param>
    /// <param name="fileds"></param>
    /// <returns></returns>
    public static int Update<T>(T entity, DataDBEntities db,
        EnumUpdateFiledType updateFiledType, params string[] fileds)
    {
        if (null == db || null == entity)
        { //     
            return 0;
        }
        Type _type = typeof(T);
        db.AttachTo(_type.Name, entity);
        if (null == fileds || fileds.Length == 0)
        { //      
            db.ObjectStateManager.ChangeObjectState(entity, System.Data.EntityState.Modified);      //          
        }
        else
        { //       
            var _stateEntry = db.ObjectStateManager.GetObjectStateEntry(entity);                    //       
            if (EnumUpdateFiledType.     == updateFiledType)
            { //       
                for (int i = 0; i < fileds.Length; i++)
                {
                    _stateEntry.SetModifiedProperty(fileds[i]);
                }
            }
            else
            { //       
                PropertyInfo[] _properties = _type.GetProperties(); //         
                foreach (PropertyInfo item in _properties)
                {
                    if ("EntityState" == item.Name || "EntityKey" == item.Name)
                    {
                        continue;
                    }
                    //      [EdmScalarPropertyAttribute(EntityKeyProperty=true, IsNullable=false)]         
                    EdmScalarPropertyAttribute _edmScalarPropertyAttribute = 
　　　　　　　　　　　　　　Attribute.GetCustomAttribute(item, typeof(EdmScalarPropertyAttribute)) as EdmScalarPropertyAttribute;
                    if (null == _edmScalarPropertyAttribute || _edmScalarPropertyAttribute.EntityKeyProperty)
                    { //          
                        continue;
                    }

                    bool _thisIsUpdateFiled = true;  //        
                    for (int i = 0; i < fileds.Length; i++)
                    {
                        if (item.Name == fileds[i])
                        {
                            _thisIsUpdateFiled = false;
                            break;
                        }
                    }
                    if (_thisIsUpdateFiled)
                        _stateEntry.SetModifiedProperty(item.Name);
                }

            }
        }
        return db.SaveChanges();
    }

    /// <summary>
    ///          
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="entity"></param>
    /// <param name="db"></param>
    /// <returns></returns>
    public static int Update<T>(T entity, DataDBEntities db)
    {
        if (null == db || null == entity)
        { //     
            return 0;
        }
        Type _type = typeof(T);
        db.AttachTo(_type.Name, entity);
        db.ObjectStateManager.ChangeObjectState(entity, System.Data.EntityState.Modified);      //          
        return db.SaveChanges();
    }

    /// <summary>
    ///          
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="entity"></param>
    /// <param name="updateFiledType"></param>
    /// <param name="fileds"></param>
    /// <returns></returns>
    public static int Update<T>(T entity, EnumUpdateFiledType updateFiledType, params string[] fileds)
    {
        if (null == entity)
        { //     
            return 0;
        }
        using (DataDBEntities db = new DataDBEntities())
        {
            Type _type = typeof(T);
            db.AttachTo(_type.Name, entity);
            if (null == fileds || fileds.Length == 0)
            { //      
                db.ObjectStateManager.ChangeObjectState(entity, System.Data.EntityState.Modified);      //          
            }
            else
            { //       
                var _stateEntry = db.ObjectStateManager.GetObjectStateEntry(entity);                    //       
                if (EnumUpdateFiledType.     == updateFiledType)
                { //       
                    for (int i = 0; i < fileds.Length; i++)
                    {
                        _stateEntry.SetModifiedProperty(fileds[i]);
                    }
                }
                else
                { //       
                    PropertyInfo[] _properties = _type.GetProperties(); //         

                    foreach (PropertyInfo item in _properties)
                    {
                        if ("EntityState" == item.Name || "EntityKey" == item.Name)
                        {
                            continue;
                        }
                        //      [EdmScalarPropertyAttribute(EntityKeyProperty=true, IsNullable=false)]         
                        EdmScalarPropertyAttribute _edmScalarPropertyAttribute = 
　　　　　　　　　　　　　　　　Attribute.GetCustomAttribute(item, typeof(EdmScalarPropertyAttribute)) as EdmScalarPropertyAttribute;
                        if (null == _edmScalarPropertyAttribute || _edmScalarPropertyAttribute.EntityKeyProperty)
                        { //          
                            continue;
                        }
                        bool _thisIsUpdateFiled = true;  //        
                        for (int i = 0; i < fileds.Length; i++)
                        {
                            if (item.Name == fileds[i])
                            {
                                _thisIsUpdateFiled = false;
                                break;
                            }
                        }
                        if (_thisIsUpdateFiled)
                            _stateEntry.SetModifiedProperty(item.Name);
                    }

                }
            }
            return db.SaveChanges();
        }
    }

    /// <summary>
    ///          
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="entity"></param>
    /// <returns></returns>
    public static int Update<T>(T entity)
    {
        if (null == entity)
        { //     
            return 0;
        }
        using (DataDBEntities db = new DataDBEntities())
        {
            Type _type = typeof(T);
            db.AttachTo(_type.Name, entity);
            db.ObjectStateManager.ChangeObjectState(entity, System.Data.EntityState.Modified);      //          
            return db.SaveChanges();
        }
    }

    #endregion

}

#region          
/// <summary>
///          
/// </summary>
public enum EnumUpdateFiledType
{
         = 1,
         = 2
}
#endregion