public T Get
     
      (int id)        {            Type type = typeof(T);            string columnStrings = string.Join(",", type.GetProperties().Select(p=>string.Format("[{0}]")));            string sql = string.Format("select {0} from  [{1}] where id={2}", columnStrings,type.Name,id);            return default(T);        }
     

 完整例子

public T Get
     
      (int id)        {            Type type = typeof(T);            string columnStrings = string.Join(",", type.GetProperties().Select(p=>string.Format("[{0}]")));            string sql = string.Format("select {0} from  [{1}] where id={2}", columnStrings,type.Name,id);            object t = Activator.CreateInstance(type);            using (SqlConnection conn = new SqlConnection("链接字符串"))            {                SqlCommand com = new SqlCommand(sql,conn);                conn.Open();                SqlDataReader reader = com.ExecuteReader();                if (reader.Read())                {                    foreach (var item in type.GetProperties())                    {                        item.SetValue(t,reader[item.Name]);                    }                }            }            return (T)t;        }