Entity FrameWork 6帮助类

 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));
         }
     }