Khozeev_8/Aithorization.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 Khozeev8
{
    public partial class Aithorization : Form
    {
        Database database = new Database();
        public Aithorization()
        {
            InitializeComponent();
            StartPosition = FormStartPosition.CenterScreen;
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            string usern = textBox1.Text;
            string pass = textBox2.Text;

            SqlDataAdapter adapter = new SqlDataAdapter();
            DataTable table = new DataTable();

            string querystring = $"SELECT Логин, Пароль FROM Пользователи WHERE Логин = '{usern}' and Пароль = '{pass}'";

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

            adapter.SelectCommand = command;
            adapter.Fill(table);

            if (table.Rows.Count == 1)
            {
                MessageBox.Show("Успешно!");
                Menu frm = new Menu();
                this.Hide();
                frm.Show();
            }
            else
                MessageBox.Show("Неверные данные");


        }

        private void panel2_Paint(object sender, PaintEventArgs e)
        {

        }

        private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
        {
           
        }

        private void linkLabel1_LinkClicked_1(object sender, LinkLabelLinkClickedEventArgs e)
        {
            Registration frm = new Registration();
            this.Hide();
            frm.Show();
        }
    }
}