判断唯一约束是否是唯一的Unique

//检查 唯一约束Name

            //检查 唯一约束Name
            int count = new BLL.Funcs().GetRecordCount(string.Format("Name={0}", model.Name));
            if (!CheckUniqueFieldByCount(EditID, count, preName, model.Name))
            {
                FineUI.Alert.Show(Resources.WebResource.SaveFailed);
                return;
            }

//新增和编辑的唯一验证不一样，必须分别判断：

        /// <summary>
        /// 检查唯一约束
        /// </summary>
        /// <param name="editId">编辑id</param>
        /// <param name="count">根据当前Name查询的数量</param>
        /// <param name="preName">原Name值</param>
        /// <param name="newName">新Name值</param>
        /// <returns>是否唯一</returns>
        protected bool CheckUniqueFieldByCount(int editId, int count, string preName, string newName)
        {
            if (editId > 0)
            {
                //如果已存在 不是本身的Name
                if (count > 1 || (count == 1 && newName != preName))
                {
                    return false;
                }
            }
            else
            {
                //如果已存在Name
                if (count > 0)
                {
                    return false;
                }
            }
            return true;
        }