餐桌项目删除餐桌

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;


namespace 餐厅复习
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            LoadDeskInfoByDelId(0);

        }
        string str = "Data Source=.;Initial Catalog=mysql;Integrated Security=True";
        private void LoadDeskInfoByDelId(int p)
        {
            //查询
            List<DeskInfo> list = new List<DeskInfo>();
            
            string sql = "select * from DeskInfo where DeskDelFlag =" + p;
            SqlConnection con = new SqlConnection(str);
            con.Open();
            SqlCommand cmd = new SqlCommand(sql, con);
            SqlDataReader reader = cmd.ExecuteReader();
            if (reader.HasRows)
            {
                while (reader.Read())
                {
                    list.Add(new DeskInfo()
                                   {
                                       DeskId = Convert.ToInt32(reader["DeskId"]),
                                       DeskName = reader["DeskName"].ToString(),
                                       DeskNamePinYin = reader["DeskNamePinYin"].ToString(),
                                       DeskNum = reader["DeskNum"].ToString()
                                   });
                }
            }
            dgv.DataSource = list;
            dgv.Rows[0].Selected = false;
            dgv.AutoGenerateColumns = false;

            con.Dispose();
            cmd.Dispose();
            reader.Dispose();
        }

        private void btnOK_Click(object sender, EventArgs e)
        {
            //添加
            string sql = string.Format("insert into DeskInfo(DeskName,DeskNamePinYin,DeskDelFlag,DeskNum) values ('{0}','{1}',0,'{2}')",txtName.Text,txtPinYin.Text,txtNum.Text);
            SqlConnection con = new SqlConnection(str);
            con.Open();
            SqlCommand cmd = new SqlCommand(sql,con);
            cmd.ExecuteNonQuery();
            LoadDeskInfoByDelId(0);
            con.Dispose();
            cmd.Dispose();
        }

        private void btnDel_Click(object sender, EventArgs e)
        {
            //删除
            int delId = Convert.ToInt32(dgv.SelectedRows[0].Cells[0].Value);
            string sql = "update DeskInfo set DeskDelFlag = 1 where DeskId = " + delId;
            SqlConnection con = new SqlConnection(str);
            con.Open();
            SqlCommand cmd = new SqlCommand(sql,con);
            cmd.ExecuteNonQuery();
            LoadDeskInfoByDelId(0);



            con.Dispose();
            cmd.Dispose();
        }



    }
}