---

using System;
using System.Data.SqlClient;
using System.Windows.Forms;
using WindowsFormsApp3;

namespace WindowsFormsApp3
{
    public partial class Form1 : Form
    {
        // ⚙️ замени строку подключения на свою
        SqlConnection con = new SqlConnection(
            "Server=ZUZURIES;Database=Дэмка;Trusted_Connection=True;");

        public Form1()
        {
            InitializeComponent();
            con.Open();
            new SqlCommand(
                "IF OBJECT_ID('users') IS NULL " +
                "CREATE TABLE users(login NVARCHAR(50), pass NVARCHAR(50))",
                con).ExecuteNonQuery();
            this.register.Click += new EventHandler(this.register_Click);
            this.loginBtn.Click += new EventHandler(this.loginBtn_Click);
            this.guestBtn.Click += new EventHandler(this.guestBtn_Click);

        }

        private void register_Click(object sender, EventArgs e)
        {
            new SqlCommand(
      $"INSERT INTO users (login, password, role) VALUES('{login.Text}','{password.Text}','client')", con)
      .ExecuteNonQuery();

            MessageBox.Show("Пользователь добавлен!");
        }

        private void loginBtn_Click(object sender, EventArgs e)
        {
            var cmd = new SqlCommand(
                $"SELECT * FROM users WHERE login='{login.Text}' AND password='{password.Text}'",
                con);
            var r = cmd.ExecuteReader();
            if (r.Read()) { new Form2().Show(); Hide(); }
            else MessageBox.Show("Неверные данные!");
            r.Close();
        }

        private void guestBtn_Click(object sender, EventArgs e)
        {
            new Form2().Show(); Hide();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

       
    }
}