C＃：插入，删除，保存，取消tabledata的按钮

Question

我正在与丹麦奥尔堡大学的一群同学一起开展一个项目，我们必须在那里编写IT系统代码。我们正在使用C＃，现在我们不再受到进一步的发展。我正在使用系统的一部分，其中admninistator可以处理来自数据库的不同表。我可以通过使用组合框选择哪一个来获取数据网格中显示的表格。 现在的问题是，我无法弄清楚如何制作一个保存，删除，插入和清除/取消按钮，可以处理特定的选定表并更新正确的一个，尽管我已经尝试了多个灵魂，但似乎没有一个工作。
DataSet包含5个表： DataSet = p4DataSet。 表：customer_table，employee_table，shop_table，order_table和product_table。

希望有人可以帮助提出如何使这项工作的建议。

这是我到目前为止的代码：

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 MySql.Data.MySqlClient;
using MySql.Data;

namespace AdminFinal
{
    public partial class Form1 : Form
    {
        MySqlDataAdapter daTableinfo;
        DataSet dsTableinfo;

        string connStr = "server=localhost;user=root;database=p4;port=3306;password=fordgt40;charset=latin1;";

        public Form1()
        {
        InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            {
                if (comboBox1.SelectedItem == "Kunder")
                {

                    MySqlConnection conn = new MySqlConnection(connStr);
                    try
                    {
                        label2.Text = "Connecting to MySQL...";

                        string sql = "SELECT * FROM customer_table";
                        daTableinfo = new MySqlDataAdapter(sql, conn);
                        MySqlCommandBuilder cb = new MySqlCommandBuilder(daTableinfo);

                        dsTableinfo = new DataSet();
                        daTableinfo.Fill(dsTableinfo, "customer_table");
                        dataGridView1.DataSource = dsTableinfo;
                        dataGridView1.DataMember = "customer_table";
                    }
                    catch (Exception ex)
                    {
                        label2.Text = ex.ToString();
                    }
                }
                else if (comboBox1.SelectedItem == "Ansatte")
                {

                    MySqlConnection conn = new MySqlConnection(connStr);
                    try
                    {
                        label2.Text = "Connecting to MySQL...";

                        string sql = "SELECT * FROM employee_table";
                        daTableinfo = new MySqlDataAdapter(sql, conn);
                        MySqlCommandBuilder cb = new MySqlCommandBuilder(daTableinfo);

                        dsTableinfo = new DataSet();
                        daTableinfo.Fill(dsTableinfo, "employee_table");
                        dataGridView1.DataSource = dsTableinfo;
                        dataGridView1.DataMember = "employee_table";
                    }
                    catch (Exception ex)
                    {
                        label2.Text = ex.ToString();
                    }
                }
                else if (comboBox1.SelectedItem == "Produkter")
                {

                    MySqlConnection conn = new MySqlConnection(connStr);
                    try
                    {
                        label2.Text = "Connecting to MySQL...";

                        string sql = "SELECT * FROM order_table";
                        daTableinfo = new MySqlDataAdapter(sql, conn);
                        MySqlCommandBuilder cb = new MySqlCommandBuilder(daTableinfo);

                        dsTableinfo = new DataSet();
                        daTableinfo.Fill(dsTableinfo, "order_table");
                        dataGridView1.DataSource = dsTableinfo;
                        dataGridView1.DataMember = "order_table";
                    }
                    catch (Exception ex)
                    {
                        label2.Text = ex.ToString();
                    }
                }
                else if (comboBox1.SelectedItem == "Ordre")
                {

                    MySqlConnection conn = new MySqlConnection(connStr);
                    try
                    {
                        label2.Text = "Connecting to MySQL...";

                        string sql = "SELECT * FROM product_table";
                        daTableinfo = new MySqlDataAdapter(sql, conn);
                        MySqlCommandBuilder cb = new MySqlCommandBuilder(daTableinfo);

                        dsTableinfo = new DataSet();
                        daTableinfo.Fill(dsTableinfo, "product_table");
                        dataGridView1.DataSource = dsTableinfo;
                        dataGridView1.DataMember = "product_table";
                    }
                    catch (Exception ex)
                    {
                        label2.Text = ex.ToString();
                    }
                }
                else if (comboBox1.SelectedItem == "Butikker")
                {

                    MySqlConnection conn = new MySqlConnection(connStr);
                    try
                    {
                        label2.Text = "Connecting to MySQL...";

                        string sql = "SELECT * FROM shop_table";
                        daTableinfo = new MySqlDataAdapter(sql, conn);
                        MySqlCommandBuilder cb = new MySqlCommandBuilder(daTableinfo);

                        dsTableinfo = new DataSet();
                        daTableinfo.Fill(dsTableinfo, "shop_table");
                        dataGridView1.DataSource = dsTableinfo;
                        dataGridView1.DataMember = "shop_table";
                    }
                    catch (Exception ex)
                    {
                        label2.Text = ex.ToString();
                    }
                }
                else
                {
                    label2.Text = "Vælg en tabel at arbejde med...";
                }
            }
        }

        private void btnAdd_Click(object sender, EventArgs e)
        {
            this.p4DataSetBindingSource.AddNew();

        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            this.Validate();
            this.p4DataSetBindingSource.EndEdit();
          //  this.p4DataSet.UpdateAll(this.p4DataSet);
        }

        private void btnDelete_Click(object sender, EventArgs e)
        {
            this.p4DataSetBindingSource.RemoveCurrent();
        }
    }
}

非常感谢提前。

丹麦尼古拉