清空剃须刀页面检查 ID 是否存在

Question

对于我自己的项目，我希望能够删除提示文章，这是有效的。 但我知道我有一个问题，它也会删除不存在的提示文章。 有人知道如何解决这个问题吗？

提示文章管理器中的代码：

 *//Delete tip article in db
        public bool DeleteTipArticle(int articleNumber)
        {
                FillTipArticleList();
                return tipArticleDB.DeleteDb(articleNumber);          
        }*

数据库中的代码：

//Delete the tip article for the tiparticle database
        public bool DeleteDb(int articleNumber)
        {
            MySqlConnection connection = new MySqlConnection(databaseConnection);

            //Sql string for deleting the tip article
            string sql = "DELETE FROM tiparticle WHERE ArticleNumber = @ArticleNumber";

            MySqlCommand command = new MySqlCommand(sql, connection);
            command.Parameters.AddWithValue("@ArticleNumber", articleNumber);

            try
            {
                connection.Open();
                int amount = command.ExecuteNonQuery();
                return amount > 0;
            }
            catch (MySqlException ex)
            {
                return false;
            }
            catch (FormatException ex)
            {
                return false;
            }
            catch (NullReferenceException ex)
            {
                return false;
            }
            finally
            {
                if (connection.State == System.Data.ConnectionState.Open)
                {
                    connection.Close();
                }
            }
        }

剃刀页面背后的代码：

[Authorize(Roles = "admin")]
    public class DeleteTipArticleModel : PageModel
    {
        [BindProperty]
        public int articleNumber { get; set; }

        public void OnGet()
        {
        }
        public IActionResult OnPost()
        {
            if (ModelState.IsValid)
            {
                string message = "The tip article has been deleted!";
                ViewData["Message"] = message;

                TipArticleManager deleteToTipArticleDatabase = new TipArticleManager();
                deleteToTipArticleDatabase.DeleteTipArticle(articleNumber);

                return Page();
            }
            else
            {
                ViewData["Message"] = "Please enter all data fields";
                return Page();
            }
        }
    }

我认为我必须对返回的金额> 0 做一些事情，但我不确定在哪里以及如何执行此操作。

Answer 1

可以查看bool succeeded = deleteToTipArticleDatabase.DeleteTipArticle(articleNumber);的返回值检查金额 > 0。

[Authorize(Roles = "admin")]
public class DeleteTipArticleModel : PageModel
{
    [BindProperty]
    public int articleNumber { get; set; }

    public void OnGet()
    {
    }
    public IActionResult OnPost()
    {
        if (ModelState.IsValid)
        {
            TipArticleManager deleteToTipArticleDatabase = new TipArticleManager();
            bool succeeded =   DeleteToTipArticleDatabase.DeleteTipArticle(articleNumber);
            if(succeeded)
            {         
                 string message = "The tip article has been deleted!";
                 ViewData["Message"] = message;
            }
            return Page();
        }
        else
        {
            ViewData["Message"] = "Please enter all data fields";
            return Page();
        }
    }
}

否则，您可以对文章编号进行数据库调用，以查看它是否已经存在。