VINIL.APP/proba/Form/MainMenu.cs

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 System.Data.SqlClient;

namespace proba
{
    public partial class MainMenu : Form
    {
        DataBase dataBase = new DataBase();
        public MainMenu()
        {
            InitializeComponent();
            dataBase.openConnection();
            SqlCommand sqlCommand_role = new SqlCommand($"SELECT R.role From Employee E inner join Roles R ON E.id_role = R.id_role WHERE E.login = '{PosleVHODA.login}'", dataBase.GetConnection());
            string role = sqlCommand_role.ExecuteScalar().ToString();
            if (role == "Администратор")
            {
                pictureBox_Employee.Visible = true;
                label_editingEmployee.Visible = true;
                label_employee.Visible = true;
            }
            else if(role == "Кассир")
            {
                pictureBox_personal_area.Visible = true;
                label_personal_area.Visible = true;
            }
            dataBase.closeConnection();
        }

        private void ButtonPostavshiki_Click(object sender, EventArgs e)
        {
            this.Hide();
            Postavshiki postavshiki = new Postavshiki();
            postavshiki.Show();
        }
        private void ButtonNomenklatura_Click(object sender, EventArgs e)
        {
            this.Hide();
            Nomenklatura nomenklatura = new Nomenklatura();
            nomenklatura.ShowDialog();
        }
        public void global_FormClosed(object sender, EventArgs e)
        {
            Application.Exit();
        }
        private void button_nomenklaturaAdd_Click(object sender, EventArgs e)
        {
            this.Hide();
            Nomenklaturaadd nomenklatura_Add = new Nomenklaturaadd();
            nomenklatura_Add.ShowDialog();
        }
        private void ButtonProdaja_Click(object sender, EventArgs e)
        {
            this.Hide();
            Sales sales = new Sales();
            sales.ShowDialog();
        }

        private void label10_Click(object sender, EventArgs e)
        {
            this.Hide();           
            Postavshiki_add postavshiki_Add = new Postavshiki_add();
            postavshiki_Add.ShowDialog();
        }

        private void button_Country_Click(object sender, EventArgs e)
        {
            this.Hide();
            Country country = new Country();
            country.ShowDialog();
        }

        private void button_Country_add_Click(object sender, EventArgs e)
        {
            this.Hide();
            CountryAdd countryAdd = new CountryAdd();
            countryAdd.ShowDialog();
        }

        private void button_salesList_Click(object sender, EventArgs e)
        {
            this.Hide();
            Form2 form2 = new Form2();
            form2.ShowDialog();
        }

        private void button_genre_Click(object sender, EventArgs e)
        {
            this.Hide();
            Genre genre = new Genre();
            genre.ShowDialog();
        }

        private void label_genre_add_Click(object sender, EventArgs e)
        {
            this.Hide();
            Genre_add genre_Add = new Genre_add();
            genre_Add.ShowDialog();
        }

        private void button_Performer_Click(object sender, EventArgs e)
        {
            this.Hide();
            Performer performer = new Performer();
            performer.ShowDialog();
        }

        private void label_performer_Click(object sender, EventArgs e)
        {
            this.Hide();
            Performer_add performer_Add = new Performer_add();
            performer_Add.ShowDialog();
        }

        private void button_edition_Click(object sender, EventArgs e)
        {
            this.Hide();
            Издатель издатель = new Издатель();
            издатель.ShowDialog();
        }

        private void label_efition_Click(object sender, EventArgs e)
        {
            this.Hide();
            EditionAdd editionAdd = new EditionAdd();
            editionAdd.ShowDialog();
        }

        private void label_personal_area_Click(object sender, EventArgs e)
        {
            this.Hide();
            PersonalArea personalArea = new PersonalArea();
            personalArea.ShowDialog();
        }

        private void pictureBox_personal_area_Click(object sender, EventArgs e)
        {
            this.Hide();
            PersonalArea personalArea = new PersonalArea();
            personalArea.ShowDialog();
        }

        private void label_editingEmployee_Click(object sender, EventArgs e)
        {
            this.Hide();
            Employee employee = new Employee();
            employee.ShowDialog();
        }

        private void pictureBox_Employee_Click(object sender, EventArgs e)
        {
            this.Hide();
            Employee employee = new Employee();
            employee.ShowDialog();
        }
    }
}