SQLParameter[]安全传值 和 DataTable与List<T>的运用

将DataTable中的数据装到List<T>中

 

/// <summary>
        /// 返回所有类别集合
        /// </summary>
        /// <returns></returns>
        public List<Category> Select()
        {
            List<Category> list = new List<Category>();
            string sql = "select id,caname,pid from nn_category";
            DataTable dt = helper.ExecuteQuery(sql);
            foreach (DataRow row in dt.Rows)
            {
                string id = row[0].ToString();
                string caname = row[1].ToString();
                string pid = row[2].ToString();
                list.Add(new Category() { Id = id, Caname = caname, Pid = pid });
            }
            return list;
        }

将值安全的传到SQL语句中执行

/// <summary>
        /// 修改分类
        /// </summary>
        /// <param name="id">要修改的ID</param>
        /// <param name="pid">修改后的分类父ID</param>
        /// <returns></returns>
        public bool Update(string id, string pid)
        {
            string sql = "update nn_category set pid=@pid where id=@id";
            SQLParameter[] paras = new SQLParameter[]{
                   new SQLParameter("@id",(id as object)),
                   new SQLParameter("@pid",(pid as object)) 
            };
            return helper.ExecuteNonQuery(sql, paras);
        }