解决EF 4.0 中数据缓存机制

EF4.0默认开启缓存机制，如果想要禁用缓存机制的话，则须加上一句话：_db.CreateObjectSet().MergeOption = MergeOption.OverwriteChanges;

 public IQueryable<T> LoadEntities(Func<T, bool> whereLambda){try{var set = _db.CreateObjectSet<T>();set.MergeOption = MergeOption.OverwriteChanges;var entities = set.Where<T>(whereLambda).AsQueryable();//var entities = _db.CreateObjectSet<T>().Where<T>(whereLambda).AsQueryable();return entities;}catch (Exception ex){Logger.Error("LoadEntities Error！", ex);throw new Exception("LoadEntities Fail", ex);}}

这样，每次查询的时候都会去数据库查询最新的数据！