Delete data row from DB in DataGridView winforms?

问题:

i want to delete the row of data from the database, currently i can delete the row of data by clicking on the delete button, but the database Table is not updated, how do i do so?

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;

namespace project
{
    public partial class frmTestPrint : Form
    {
        public frmTestPrint()
        {
            InitializeComponent();
        }

        private void frmTestPrint_Load(object sender, EventArgs e)
        {
            // TODO: This line of code loads data into the 'usersDataSet1.Booking' table. You can move, or remove it, as needed.
            this.bookingTableAdapter.Fill(this.usersDataSet1.Booking);

        }


        private void btnDelete_Click(object sender, EventArgs e)
        {
            dataGridView1.Rows.RemoveAt(dataGridView1.CurrentRow.Index);
        }
    }
}

回答1:

private void Delete()
    {

        int i = 0;
        con1 = getConnection();
        con1.Open();
        SqlCommand storedProcedureCommand = con1.CreateCommand();
        storedProcedureCommand.CommandType = CommandType.Text;
        storedProcedureCommand.CommandText = "DELETE FROM name of your table WHERE pkeyID = @pkeyID";

        SqlParameter inparam2 = new SqlParameter("@pkeyID", SqlDbType.Int);
        inparam2.Direction = ParameterDirection.Input;
        inparam2.Value = Convert.ToInt32(dataGridView2.Rows[i].Cells[0].Value);
        storedProcedureCommand.Parameters.Add(inparam2);
        storedProcedureCommand.ExecuteNonQuery();

    }    

回答2:

This is only to delete one at a time. I am still working on multiple deletes.

        if (MessageBox.Show("Sure you wanna delete?", "Warning", MessageBoxButtons.YesNo) == System.Windows.Forms.DialogResult.Yes)
        {
            //get the index from the dataGridView
            int rowIndex = table1DataGridView.CurrentCell.RowIndex;
            //Remove from both the actual database & datagridview
            table1BindingSource.RemoveAt(rowIndex);
            //update table 1
            this.table1TableAdapter.Update(this.maquinasDataSet.Table1);
            //load table 1
            this.table1TableAdapter.Fill(this.maquinasDataSet.Table1);
        }

回答3:

You're not actually impacting the database at all. Perhaps this will help:

How to delete a selected DataGridViewRow and update a connected database table?

Have you explored the .Update method you get with the TableAdapter? I think that should cover what you're after. http://msdn.microsoft.com/en-us/library/bz9tthwx(v=vs.100).aspx

Does this work:

private void btnDelete_Click(object sender, EventArgs e)
    {
        dataGridView1.Rows.RemoveAt(dataGridView1.CurrentRow.Index);
        this.bookingTableAdapter.Update(this.usersDataSet1.Booking);
    }

if that doesn't work, you're going to have to come back w/ an error message or hopefully someone who knows what they're doing can come bail me out...

回答4:

Delete a value from the data grid using DataGridviewBUttonColumn

private void delete_record()
    {

         if (dataGridView1.Rows.Count > 1 && dataGridView1.SelectedRows[0].Index != dataGridView1.Rows.Count - 1)
        {
            try
            {
                //am taking connection string using a class called "sqlconnection_imventory()"
                SqlConnection conn = Connection.sqlconnection_imventory();
                //Cell[0] is my button column & Cell[1] is SID coumn
                string a = dataGridView1.SelectedRows[0].Cells[1].Value.ToString();
                string sql = "DELETE FROM grades WHERE SID='" + a + "'";
                conn.Open();
                SqlCommand delcmd = new SqlCommand(sql, conn);
                delcmd.Connection = conn;
                delcmd.ExecuteNonQuery();
                conn.Close();
                dataGridView1.Rows.RemoveAt(dataGridView1.SelectedRows[0].Index);
                MessageBox.Show("deleted");
            }
            catch (Exception)
            {

                throw;
            } 
        }
    }