PerevozkiBD/Perevozki/Admin.cs

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


namespace Perevozki
{
    public partial class Admin : Form
    {
        public Admin()
        {
            InitializeComponent();
            StartPosition = FormStartPosition.CenterScreen;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            DB dataBase = new DB();

            var log = textBox1.Text;
            var pass = textBox2.Text;

            string querystring = $"insert into Polzovateli (Login, Password) values('{log}', '{pass}')";


            SqlCommand command = new SqlCommand(querystring, dataBase.GetConnection());

            dataBase.OpenConnection();

            if(command.ExecuteNonQuery() ==1 )
            {
                MessageBox.Show("Пользователь добавлен!");
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            DB dataBase = new DB();

           

         

            var ID = textBox3.Text;
         

            string querystring = $"DELETE FROM Polzovateli WHERE IDUser = {ID}";

            SqlCommand command = new SqlCommand(querystring, dataBase.GetConnection());
            dataBase.OpenConnection();
 
                if (command.ExecuteNonQuery() == 1)
                {
                    MessageBox.Show("Пользователь удален!");
                }
                else
                {
                    MessageBox.Show("Такого пользователя нету");
                }

        }

        private void button3_Click(object sender, EventArgs e)
        {

        }

        private void button3_Click_1(object sender, EventArgs e)
        {
            DB dataBase = new DB();

            var log = textBox1.Text;
            var pass = textBox2.Text;
            var ID = textBox3.Text;

            string changeQuery = $"UPDATE Polzovateli SET Login = '{log}' , Password = '{pass}' where IDUser  = '{ID}'";

            SqlCommand command = new SqlCommand(changeQuery, dataBase.GetConnection());
            dataBase.OpenConnection();
            if (command.ExecuteNonQuery() == 1)
            {
                MessageBox.Show("Данные изменены");
            }

        }

        private void button4_Click(object sender, EventArgs e)
        {
            Menu f4 = new Menu();
            f4.Show();
            Hide();
        }
    }
}