c# - 数据没有从数据库中删除

Question

在 Windows 桌面应用程序窗体中，我使用此代码从 datagridview 和数据库中删除数据，我在 dataridview 中选择了一个复选框列，如果我单击 checkbox 行正在从那一刻删除datagridview，但不是来自数据库，因此当我重新加载表单时，我可以再次看到该行，我哪里出错了？

public partial class EditEngClgList : Form
    {        
        private OleDbConnection acccon = null;
        private OleDbDataAdapter da = null;
        private DataTable dt = null;
        private BindingSource bs = null;
        private OleDbCommandBuilder cmdb = null;


        public EditEngClgList()
        {
            InitializeComponent();
            try
            {
                acccon = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=db1.mdb");
                acccon.Open();
            }
            catch (Exception err)
            {
                MessageBox.Show("Error:" + err);
            }
            string sql = "Select * From EngColeges order by EngClgID";
            da = new OleDbDataAdapter(sql, acccon);
            cmdb = new OleDbCommandBuilder(da);

            dt = new DataTable();
            da.Fill(dt);
            bs = new BindingSource();
            bs.DataSource = dt;

            dataGridView1.DataSource = bs;

            dataGridView1.Columns[1].Visible = false;
            dataGridView1.Columns[2].HeaderText = "Engineering College Name";
            dataGridView1.Columns[3].HeaderText = "Adress";
            dataGridView1.Columns[4].HeaderText = "Entrance Type";
            dataGridView1.Columns[2].Width = 400;
        }

        private void button4_Click(object sender, EventArgs e)
        {
            List<int> checkedclg = new List<int>();
            DataRow dr;
            List<int> checkedclgid = new List<int>();
            for (int i = 0; i <= dataGridView1.RowCount - 1; i++)
            {
                if (Convert.ToBoolean(dataGridView1.Rows[i].Cells["Delete"].Value) == true)
                {
                    checkedclg.Add(i);
                    checkedclgid.Add(Convert.ToInt16(dataGridView1.Rows[i].Cells["Delete"].Value)); 
                }
            }
            foreach (int k in checkedclg)
            {
                dr = dt.Rows[k];               
                dt.Rows[k].Delete();
                foreach (int j in checkedclgid)
                {
                    OleDbCommand oleDbCommand = new OleDbCommand("DELETE FROM EngColeges WHERE EngClgID = @clgID", acccon);
                    oleDbCommand.Parameters.Add("@clgID", OleDbType.Integer).Value = j;
                    oleDbCommand.Prepare();
                    oleDbCommand.ExecuteNonQuery();

                }
            }
        }

Answer 1

if (Convert.ToBoolean(dataGridView1.Rows[i].Cells["Delete"].Value) == true)
{
    checkedclg.Add(i);
    checkedclgid.Add(Convert.ToInt16(dataGridView1.Rows[i].Cells["Delete"].Value));
}

似乎传递给 Convert.ToInt16 的单元格值有误？它使用“已删除”列而不是您的 ID 列。

也可以使用where in子句删除一条sql语句中的所有行，例如:DELETE FROM table WHERE id IN (1, 2, 3, 4)