entity framework 6 通用数据类

原文  http://blog.csdn.net/laokaizzz/article/details/25730813

 public class BaseDAL
     {
   string strConn = "";
   public BaseDAL(string connString)
   {
       strConn = connString;
   }

   #region 通用增删改查
   #region 非原始sql语句方式
   /// <summary>
   /// 新增
   /// </summary>
   /// <param name="entity">实体</param>
   /// <returns>返回受影响行数</returns>
   public bool Add<T>(T entity) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     db.Entry<T>(entity).State = EntityState.Added;
     return db.SaveChanges() > ;
       }
   }

   /// <summary>
   /// 修改
   /// </summary>
   /// <param name="entity">实体</param>
   /// <returns>返回受影响行数</returns>
   public bool Update<T>(T entity) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     db.Set<T>().Attach(entity);
     db.Entry<T>(entity).State = EntityState.Modified;
     return db.SaveChanges() > ;
       }
   }

   /// <summary>
   /// 删除
   /// </summary>
   /// <param name="entity">实体</param>
   /// <returns>返回受影响行数</returns>
   public bool Delete<T>(T entity) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     db.Set<T>().Attach(entity);
     db.Entry<T>(entity).State = EntityState.Deleted;
     return db.SaveChanges() > ;
       }
   }

   /// <summary>
   /// 根据条件删除
   /// </summary>
   /// <param name="deleWhere">删除条件</param>
   /// <returns>返回受影响行数</returns>
   public bool DeleteByConditon<T>(Expression<Func<T, bool>> deleWhere) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     List<T> entitys = db.Set<T>().Where(deleWhere).ToList();
     entitys.ForEach(m => db.Entry<T>(m).State = EntityState.Deleted);
     return db.SaveChanges() > ;
       }
   }

   /// <summary>
   /// 查找单个
   /// </summary>
   /// <param name="id">主键</param>
   /// <returns></returns>
   public T GetSingleById<T>(int id) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     return db.Set<T>().Find(id);
       }
   }

   /// <summary>
   /// 查找单个
   /// </summary>
   /// <param name="seleWhere">查询条件</param>
   /// <returns></returns>
   public T GetSingle<T>(Expression<Func<T, bool>> seleWhere) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     return db.Set<T>().AsExpandable().FirstOrDefault(seleWhere);
       }
   }

   /// <summary>
   /// 获取所有实体集合
   /// </summary>
   /// <returns></returns>
   public List<T> GetAll<T>() where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     return db.Set<T>().AsExpandable().ToList<T>();
       }
   }

   /// <summary>
   /// 获取所有实体集合(单个排序)
   /// </summary>
   /// <returns></returns>
   public List<T> GetAll<T, Tkey>(Expression<Func<T, Tkey>> orderWhere, bool isDesc) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     return CommonSort(db.Set<T>().AsExpandable(), orderWhere, isDesc).ToList<T>();
       }
   }

   /// <summary>
   /// 获取所有实体集合(多个排序)
   /// </summary>
   /// <returns></returns>
   public List<T> GetAll<T>(params OrderModelField[] orderByExpression) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     return CommonSort(db.Set<T>().AsExpandable(), orderByExpression).ToList();
       }
   }

   /// <summary>
   /// 单个排序通用方法
   /// </summary>
   /// <typeparam name="Tkey">排序字段</typeparam>
   /// <param name="data">要排序的数据</param>
   /// <param name="orderWhere">排序条件</param>
   /// <param name="isDesc">是否倒序</param>
   /// <returns>排序后的集合</returns>
   public IQueryable<T> CommonSort<T, Tkey>(IQueryable<T> data, Expression<Func<T, Tkey>> orderWhere, bool isDesc) where T : class
   {
       if (isDesc)
       {
     return data.OrderByDescending(orderWhere);
       }
       else
       {
     return data.OrderBy(orderWhere);
       }
   }

   /// <summary>
   /// 多个排序通用方法
   /// </summary>
   /// <typeparam name="Tkey">排序字段</typeparam>
   /// <param name="data">要排序的数据</param>
   /// <param name="orderWhereAndIsDesc">字典集合(排序条件,是否倒序)</param>
   /// <returns>排序后的集合</returns>
   public IQueryable<T> CommonSort<T>(IQueryable<T> data, params OrderModelField[] orderByExpression) where T : class
   {
       //创建表达式变量参数
       var parameter = Expression.Parameter(typeof(T), "o");

       if (orderByExpression != null && orderByExpression.Length > )
       {
     for (int i = ; i < orderByExpression.Length; i++)
     {
         //根据属性名获取属性
         var property = typeof(T).GetProperty(orderByExpression[i].PropertyName);
         //创建一个访问属性的表达式
         var propertyAccess = Expression.MakeMemberAccess(parameter, property);
         var orderByExp = Expression.Lambda(propertyAccess, parameter);

         string OrderName = "";
         if (i > )
         {
       OrderName = orderByExpression[i].IsDESC ? "ThenByDescending" : "ThenBy";
         }
         else
       OrderName = orderByExpression[i].IsDESC ? "OrderByDescending" : "OrderBy";

         MethodCallExpression resultExp = Expression.Call(typeof(Queryable), OrderName, new Type[] { typeof(T), property.PropertyType },
       data.Expression, Expression.Quote(orderByExp));

         data = data.Provider.CreateQuery<T>(resultExp);
     }
       }
       return data;
   }

   /// <summary>
   /// 根据条件查询实体集合
   /// </summary>
   /// <param name="seleWhere">查询条件 lambel表达式</param>
   /// <returns></returns>
   public List<T> GetList<T>(Expression<Func<T, bool>> seleWhere) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     return db.Set<T>().AsExpandable().Where(seleWhere).ToList();
       }
   }

   /// <summary>
   /// 根据条件查询实体集合
   /// </summary>
   /// <param name="seleWhere">查询条件 lambel表达式</param>
   /// <returns></returns>
   public List<T> GetList<T, TValue>(Expression<Func<T, TValue>> seleWhere, IEnumerable<TValue> conditions) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {

     return db.Set<T>().AsExpandable().WhereIn<T, TValue>(seleWhere, conditions).ToList();
       }
   }

   /// <summary>
   /// 根据条件查询实体集合(单个字段排序)
   /// </summary>
   /// <param name="seleWhere">查询条件 lambel表达式</param>
   /// <returns></returns>
   public List<T> GetList<T, Tkey>(Expression<Func<T, bool>> seleWhere, Expression<Func<T, Tkey>> orderWhere, bool isDesc) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     return CommonSort(db.Set<T>().AsExpandable().Where(seleWhere), orderWhere, isDesc).ToList();
       }
   }

   /// <summary>
   /// 根据条件查询实体集合(多个字段排序)
   /// </summary>
   /// <param name="seleWhere">查询条件 lambel表达式</param>
   /// <returns></returns>
   public List<T> GetList<T>(Expression<Func<T, bool>> seleWhere, params OrderModelField[] orderByExpression) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     return CommonSort(db.Set<T>().AsExpandable().Where(seleWhere), orderByExpression).ToList();
       }
   }

   /// <summary>
   /// 获取分页集合(无条件无排序)
   /// </summary>
   /// <returns></returns>
   public List<T> GetListPaged<T, Tkey>(int pageIndex, int pageSize, out int totalcount) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     totalcount = db.Set<T>().AsExpandable().Count();//获取总数
     //需要增加AsExpandable(),否则查询的是所有数据到内存，然后再排序  AsExpandable是linqkit.dll中的方法
     return db.Set<T>().AsExpandable().Skip((pageIndex - ) * pageSize).Take(pageSize).ToList();
       }
   }

   /// <summary>
   /// 获取分页集合(无条件单个排序)
   /// </summary>
   /// <returns></returns>
   public List<T> GetListPaged<T, Tkey>(int pageIndex, int pageSize, Expression<Func<T, Tkey>> orderWhere, bool isDesc, out int totalcount) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     totalcount = db.Set<T>().AsExpandable().Count();//获取总数
     //需要增加AsExpandable(),否则查询的是所有数据到内存，然后再排序  AsExpandable是linqkit.dll中的方法
     return CommonSort(db.Set<T>().AsExpandable(), orderWhere, isDesc).Skip((pageIndex - ) * pageSize).Take(pageSize).ToList();
       }
   }

   /// <summary>
   /// 获取分页集合(无条件多字段排序)
   /// </summary>
   /// <returns></returns>
   public List<T> GetListPaged<T>(int pageIndex, int pageSize, out int totalcount, params OrderModelField[] orderByExpression) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     totalcount = db.Set<T>().AsExpandable().Count();//获取总数
     //需要增加AsExpandable(),否则查询的是所有数据到内存，然后再排序  AsExpandable是linqkit.dll中的方法
     return CommonSort(db.Set<T>().AsExpandable(), orderByExpression).Skip((pageIndex - ) * pageSize).Take(pageSize).ToList();
       }
   }

   /// <summary>
   /// 获取分页集合(有条件无排序)
   /// </summary>
   /// <returns></returns>
   public List<T> GetListPaged<T, Tkey>(int pageIndex, int pageSize, Expression<Func<T, bool>> seleWhere, out int totalcount) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     totalcount = db.Set<T>().AsExpandable().Where(seleWhere).Count();//获取总数
     //需要增加AsExpandable(),否则查询的是所有数据到内存，然后再排序  AsExpandable是linqkit.dll中的方法
     return db.Set<T>().AsExpandable().Where(seleWhere).Skip((pageIndex - ) * pageSize).Take(pageSize).ToList();
       }
   }

   /// <summary>
   /// 获取分页集合(有条件单个排序)
   /// </summary>
   /// <returns></returns>
   public List<T> GetListPaged<T, Tkey>(int pageIndex, int pageSize, Expression<Func<T, bool>> seleWhere,
       Expression<Func<T, Tkey>> orderWhere, bool isDesc, out int totalcount) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     totalcount = db.Set<T>().AsExpandable().Where(seleWhere).Count();//获取总数
     //需要增加AsExpandable(),否则查询的是所有数据到内存，然后再排序  AsExpandable是linqkit.dll中的方法
     return CommonSort(db.Set<T>().AsExpandable().Where(seleWhere), orderWhere, isDesc).Skip((pageIndex - ) * pageSize).Take(pageSize).ToList();
       }
   }

   /// <summary>
   /// 获取分页集合(有条件多字段排序)
   /// </summary>
   /// <returns></returns>
   public List<T> GetListPaged<T>(int pageIndex, int pageSize, Expression<Func<T, bool>> seleWhere,
       out int totalcount, params OrderModelField[] orderModelFiled) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     totalcount = db.Set<T>().AsExpandable().Where(seleWhere).Count();//获取总数
     //需要增加AsExpandable(),否则查询的是所有数据到内存，然后再排序  AsExpandable是linqkit.dll中的方法
     return CommonSort(db.Set<T>().AsExpandable().Where(seleWhere), orderModelFiled).Skip((pageIndex - ) * pageSize).Take(pageSize).ToList();
       }
   }
   #endregion

   #region 原始sql操作
   /// <summary>
   /// 执行操作
   /// </summary>
   /// <param name="sql"></param>
   /// <param name="paras"></param>
   public void ExecuteSql(string sql, params object[] paras)
   {
       using (SysDb db = new SysDb(strConn))
       {
     db.Database.ExecuteSqlCommand(sql, paras);
       }
   }

   /// <summary>
   /// 查询列表
   /// </summary>
   /// <typeparam name="T"></typeparam>
   /// <param name="sql"></param>
   /// <param name="paras"></param>
   /// <returns></returns>
   public List<T> QueryList<T>(string sql, params object[] paras) where T : class
   {
       using (SysDb db = new SysDb(strConn))
       {
     return db.Database.SqlQuery<T>(sql, paras).ToList();
       }
   }

   /// <summary>
   /// 查询单个
   /// </summary>
   /// <typeparam name="T"></typeparam>
   /// <param name="sql"></param>
   /// <param name="paras"></param>
   /// <returns></returns>
   public T QuerySingle<T>(string sql, params object[] paras) where T : class
   {
       using (SysDb<T> db = new SysDb<T>(strConn))
       {
     return db.Database.SqlQuery<T>(sql, paras).FirstOrDefault();
       }
   }

   /// <summary>
   /// 执行事务
   /// </summary>
   /// <param name="lsSql"></param>
   /// <param name="lsParas"></param>
   public void ExecuteTransaction(List<String> lsSql, List<Object[]> lsParas)
   {
       using (SysDb db = new SysDb(strConn))
       {
     using (var tran = db.Database.BeginTransaction())
     {
         try
         {
       for (int i = ; i < lsSql.Count; i++)
       {
           if (lsParas != null && lsParas.Count > )
           {
         db.Database.ExecuteSqlCommand(lsSql[i], lsParas[i]);
           }
       }
       foreach (String item in lsSql)
       {
           db.Database.ExecuteSqlCommand(item);
       }

       tran.Commit();
         }
         catch (Exception ex)
         {
       tran.Rollback();
       throw ex;
         }
     }
       }
   }
   #endregion
   #endregion

   #region 通用属性
   /// <summary>
   /// 获取数据库服务器当前时间。
   /// </summary>
   public DateTime ServerTime
   {
       get
       {
     using (SysDb db = new SysDb(strConn))
     {
         String sql = "SELECT GETDATE()";
         Object objServerTime = db.Database.SqlQuery<Object>(sql);
         return Convert.ToDateTime(objServerTime);
     }
       }
   }

   /// <summary>
   /// 获取数据库版本。
   /// </summary>
   public String DatabaseVersion
   {
       get
       {
     using (SysDb db = new SysDb(strConn))
     {
         try
         {
       String sql = "SELECT Version FROM Sys_Version";
       Object objServerTime = db.Database.SqlQuery<Object>(sql);
       return Convert.ToString(objServerTime);
         }
         catch
         {
         }
         return String.Empty;
     }
       }
   }
   #endregion

     }
     public static class QueryableExtension
     {
   /// <summary>
   /// 扩展方法  支持 in 操作
   /// </summary>
   /// <typeparam name="TEntity">需要扩展的对象类型</typeparam>
   /// <typeparam name="TValue">in 的值类型</typeparam>
   /// <param name="source">需要扩展的对象</param>
   /// <param name="valueSelector">值选择器 例如c=>c.UserId</param>
   /// <param name="values">值集合</param>
   /// <returns></returns>
   public static IQueryable<TEntity> WhereIn<TEntity, TValue>(this IQueryable<TEntity> source, Expression<Func<TEntity, TValue>> valueSelector,
     IEnumerable<TValue> values)
   {
       if (null == valueSelector) { throw new ArgumentNullException("valueSelector"); }
       if (null == values) { throw new ArgumentNullException("values"); }
       ParameterExpression p = valueSelector.Parameters.Single();

       if (!values.Any())
       {
     return source;
       }
       var equals = values.Select(value => (Expression)Expression.Equal(valueSelector.Body, Expression.Constant(value, typeof(TValue))));
       var body = equals.Aggregate<Expression>((accumulate, equal) => Expression.Or(accumulate, equal));
       return source.Where(Expression.Lambda<Func<TEntity, bool>>(body, p));
   }
     }
     public struct OrderModelField
     {

   public bool IsDESC { get; set; }
   public string PropertyName { get; set; }
     }
 dbcontext类：

 public class SysDb : DbContext
   {
     bool isNew = true;//是否是新的sql执行
     string strMsg = "";//sql执行的相关信息
     string strConn = "";//数据库连接字符串
     string UserName = "";//日志用户名称
     string AdditionalInfo = "";//日志额外信息
     public SysDb(string connString) : // 数据库链接字符串
       base(connString)
     {
       strConn = connString;
       Database.SetInitializer<SysDb>(null);//设置为空，防止自动检查和生成
       base.Database.Log = (info) => Debug.WriteLine(info);
     }

     public SysDb(string connString, string logUserName, string logAdditionalInfo) : // 数据库链接字符串
       base(connString)
     {
       strConn = connString;
       Database.SetInitializer<SysDb>(null);//设置为空，防止自动检查和生成
       UserName = logUserName;
       AdditionalInfo = logAdditionalInfo;
       base.Database.Log = AddLogger;
     }

     protected override void OnModelCreating(DbModelBuilder modelBuilder)
     {
       //去掉复数映射
       modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
       base.OnModelCreating(modelBuilder);
     }

     /// <summary>
     /// 添加日志
     /// </summary>
     /// <param name="info"></param>
     public void AddLogger(string info)
     {
       if (info != "\r\n" && (!info.Contains("Sys_EventLog")))
       {
         string strTemp = info.ToUpper().Trim();
         if (isNew)
         {
           //记录增删改
           if (strTemp.StartsWith("INSERT") || strTemp.StartsWith("UPDATE") || strTemp.StartsWith("DELETE"))
           {
             strMsg = info;
             isNew = false;
           }
         }
         else
         {
           if (strTemp.StartsWith("CLOSED CONNECTION"))
           {
             //增加新日志
             using (SysDb db = new SysDb(strConn))
             {
               try
               {
         //保存日志到数据库或其他地方

               }
               catch (Exception ex)
               {
                 using (System.IO.StreamWriter sw = new System.IO.StreamWriter(AppDomain.CurrentDomain.BaseDirectory + "//logError.txt"))
                 {
                   sw.Write(ex.Message);
                   sw.Flush();
                 }
               }
             }
             //清空
             strMsg = "";
             isNew = true;
           }
           else
           {
             strMsg += info;
           }
         }

       }
     }

   }
   public class SysDb<T> : SysDb where T : class
   {
     public SysDb(string connString) : // 数据库链接字符串
       base(connString)
     {
       Database.SetInitializer<SysDb<T>>(null);//设置为空，防止自动检查和生成
     }

     public SysDb(string connString, string logUserName, string logAdditionalInfo) : // 数据库链接字符串
       base(connString,logUserName,logAdditionalInfo)
     {
       Database.SetInitializer<SysDb<T>>(null);//设置为空，防止自动检查和生成
     }

     public DbSet<T> Entities { get; set; }
   }
 界面使用：（bll层忽略）

 public class BusinessController : Controller
   {
     //
     // GET: /Jygl/Business/
     BaseBLL basebll = new BaseBLL(WebHelper.Conn);

     public ActionResult GetXMList(int page,int rows)
     {
       int count = ;
       //查询条件
       //Expression<Func<JY_XM, bool>> searchPredicate = PredicateBuilder.True<JY_XM>();
       //searchPredicate = searchPredicate.And(c => c.UserName.Contains(""));
       Expression<Func<JY_XM, int>> keySelector = u => u.UID;
       string str = ExceptionHelper<JY_XM>.TryCatchPageQueryJson<int>(basebll.GetListPaged, page, rows, keySelector, false, out count);
       return Content(str);
     }

     [HttpPost]
     public ActionResult XMEdit(JY_XM jyxm)
     {
       basebll.Add(jyxm);
       return View();
     }

     public ActionResult GetAllGCLB()
     {

       List<DICT_GCLB> lsGCLB = basebll.GetAll<DICT_GCLB>();
       DICT_GCLB dicNew=new DICT_GCLB();
       dicNew.GCLBText="-请选择-";
       dicNew.GCLBId=;
       lsGCLB.Add(dicNew);

       return Content(WebHelper.Json(lsGCLB));
     }

     public ActionResult GetAllArea()
     {
       List<DICT_Area> lsArea = basebll.GetAll<DICT_Area>();
       DICT_Area dicNew=new DICT_Area();
       dicNew.AreaText="-请选择-";
       dicNew.AreaId=;
       lsArea.Add(dicNew);
       return Content(WebHelper.Json(lsArea));
     }
   }