Proiz/Blanki_ekzamena/Form1.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 Blanki_ekzamena
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        public DataTable Select(string selectSQL)
        {
            DataTable dataTable = new DataTable("dataBase");
            SqlConnection sqlConnection = new SqlConnection("server=ngknn.ru;Trusted_Connection=No;DataBase=31P_Trifonova_PP;User ID=31П;PWD=12357");
            sqlConnection.Open();
            SqlCommand sqlCommand = sqlConnection.CreateCommand();
            sqlCommand.CommandText = selectSQL;
            SqlDataAdapter sqlDataAdapter = new SqlDataAdapter(sqlCommand);
            sqlDataAdapter.Fill(dataTable);
            sqlConnection.Close();
            return dataTable;
        }
        private void btn_sotr_Click(object sender, EventArgs e)
        {
            if (textBox2.UseSystemPasswordChar == true)
            {
                textBox2.UseSystemPasswordChar = false;
            }
            else
            {
                textBox2.UseSystemPasswordChar = true;
            }
        }
        public bool isFormVaid(string a, string b)
        {
            if (a.ToString().Trim() == String.Empty || b.ToString().Trim() == String.Empty)
            {
                MessageBox.Show("Обезательные поля пустые", "Пожалуйста, заполните обязательные поля", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return false;
            }
            else
            {
                return true;
            }
        }
        private bool checkAdmin(string login_sotrd, string password)

        {
            const string sql = "Select * from Sotrudnik WHERE Login = @log AND [Password] = @pass and [Dolgnost]='Администратор'";
            DataTable table = new DataTable();
            SqlCommand cmd = new SqlCommand(sql, DataBase.connect());
            SqlDataAdapter adapter = new SqlDataAdapter();
            cmd.Parameters.Add(new SqlParameter("@log", SqlDbType.NVarChar, 50));
            cmd.Parameters["@log"].Value = login_sotrd;
            cmd.Parameters.Add(new SqlParameter("@pass", SqlDbType.NVarChar, 50));
            cmd.Parameters["@pass"].Value = password;
            adapter.SelectCommand = cmd;
            adapter.Fill(table);
            if (table.Rows.Count == 1)
            {
                DebugAndTrace hy = new DebugAndTrace();
                string[] opisanie = new string[4];
                using (SqlConnection connection = new SqlConnection("server=ngknn.ru;Trusted_Connection=No;DataBase=31P_Trifonova_PP;User ID=31П;PWD=12357"))
                {
                    connection.Open();

                    SqlCommand command3 = new SqlCommand("Select [Familia] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                    opisanie[0] = command3.ExecuteScalar().ToString();
                    DebugAndTrace.fio = $"{opisanie[0]}";

                    SqlCommand command4 = new SqlCommand("Select [Ima] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                    opisanie[1] = command4.ExecuteScalar().ToString();
                    DebugAndTrace.ima = $"{opisanie[1]}";

                    SqlCommand command5 = new SqlCommand("Select [Otchestvo] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                    opisanie[2] = command5.ExecuteScalar().ToString();
                    DebugAndTrace.oth = $"{opisanie[2]}";

                    SqlCommand command6 = new SqlCommand("Select [Dolgnost] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                    opisanie[3] = command6.ExecuteScalar().ToString();
                    DebugAndTrace.dol = $"{opisanie[3]}";
                }

                DebugAndTrace.login(textBox1.Text);
                return true;
            }
            else
            {
               
                return false;
            }
        }
        private bool checkOperator(string login_sotrd, string password)
        {
            const string sql = "Select * from Sotrudnik WHERE Login = @log AND [Password] = @pass and [Dolgnost]='Оператор'";
            DataTable table = new DataTable();
            SqlCommand cmd = new SqlCommand(sql, DataBase.connect());
            SqlDataAdapter adapter = new SqlDataAdapter();
            cmd.Parameters.Add(new SqlParameter("@log", SqlDbType.NVarChar, 50));
            cmd.Parameters["@log"].Value = login_sotrd;
            cmd.Parameters.Add(new SqlParameter("@pass", SqlDbType.NVarChar, 50));
            cmd.Parameters["@pass"].Value = password;
            adapter.SelectCommand = cmd;
            adapter.Fill(table);
            if (table.Rows.Count == 1)
            {
                DebugAndTrace hy = new DebugAndTrace();
                string[] opisanie = new string[4];
                using (SqlConnection connection = new SqlConnection("server=ngknn.ru;Trusted_Connection=No;DataBase=31P_Trifonova_PP;User ID=31П;PWD=12357"))
                {
                    connection.Open();

                    SqlCommand command3 = new SqlCommand("Select [Familia] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                    opisanie[0] = command3.ExecuteScalar().ToString();
                    DebugAndTrace.fio = $"{opisanie[0]}";

                    SqlCommand command4 = new SqlCommand("Select [Ima] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                    opisanie[1] = command4.ExecuteScalar().ToString();
                    DebugAndTrace.ima = $"{opisanie[1]}";

                    SqlCommand command5 = new SqlCommand("Select [Otchestvo] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                    opisanie[2] = command5.ExecuteScalar().ToString();
                    DebugAndTrace.oth = $"{opisanie[2]}";

                    SqlCommand command6 = new SqlCommand("Select [Dolgnost] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                    opisanie[3] = command6.ExecuteScalar().ToString();
                    DebugAndTrace.dol = $"{opisanie[3]}";
                }

                DebugAndTrace.login(textBox1.Text);
                return true;
            }
            else
            {
                
                return false;
            }
        }
        private bool checkSotr(string login_sotrd, string password)
        {
            const string sql = "Select * from Sotrudnik WHERE Login = @log AND [Password] = @pass and [Dolgnost]='Сотрудник'";
            DataTable table = new DataTable();
            SqlCommand cmd = new SqlCommand(sql, DataBase.connect());
            SqlDataAdapter adapter = new SqlDataAdapter();
            cmd.Parameters.Add(new SqlParameter("@log", SqlDbType.NVarChar, 50));
            cmd.Parameters["@log"].Value = login_sotrd;
            cmd.Parameters.Add(new SqlParameter("@pass", SqlDbType.NVarChar, 50));
            cmd.Parameters["@pass"].Value = password;
            adapter.SelectCommand = cmd;
            adapter.Fill(table);
            if (table.Rows.Count == 1)
            {
                DebugAndTrace hy = new DebugAndTrace();
                string[] opisanie = new string[4];
                using (SqlConnection connection = new SqlConnection("server=ngknn.ru;Trusted_Connection=No;DataBase=31P_Trifonova_PP;User ID=31П;PWD=12357"))
                {
                    connection.Open();
                
                    SqlCommand command3 = new SqlCommand("Select [Familia] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                    opisanie[0] = command3.ExecuteScalar().ToString();
                    DebugAndTrace.fio = $"{opisanie[0]}";

                    SqlCommand command4 = new SqlCommand("Select [Ima] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                    opisanie[1] = command4.ExecuteScalar().ToString();
                    DebugAndTrace.ima = $"{opisanie[1]}";

                    SqlCommand command5 = new SqlCommand("Select [Otchestvo] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                    opisanie[2] = command5.ExecuteScalar().ToString();
                    DebugAndTrace.oth = $"{opisanie[2]}";

                    SqlCommand command6 = new SqlCommand("Select [Dolgnost] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                    opisanie[3] = command6.ExecuteScalar().ToString();
                    DebugAndTrace.dol = $"{opisanie[3]}";
                }

                DebugAndTrace.login(textBox1.Text);
                return true;
            }
            else
            {
                MessageBox.Show("Неправильный логин или пароль! Повторите ввод!");
                return false;
            }
        }
        private void btn_reg_Click(object sender, EventArgs e)
        {
            if (isFormVaid(textBox1.Text, textBox2.Text))
            {
                if (checkAdmin(textBox1.Text, textBox2.Text))
                {

                 
                    Admin nh = new Admin();
                    string[] opisanie = new string[3];
                    using (SqlConnection connection = new SqlConnection("server=ngknn.ru;Trusted_Connection=No;DataBase=31P_Trifonova_PP;User ID=31П;PWD=12357"))
                    {
                        connection.Open();
                        SqlCommand command = new SqlCommand("Select [Familia] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'and [Dolgnost]='Администратор'", connection);
                        opisanie[0] = command.ExecuteScalar().ToString();
                        Admin.familia = $"{opisanie[0]}";

                        SqlCommand command1 = new SqlCommand("Select [Ima] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'and [Dolgnost]='Администратор'", connection);
                        opisanie[1] = command1.ExecuteScalar().ToString();
                        Admin.ima = $"{opisanie[1]}";

                        SqlCommand command2 = new SqlCommand("Select [Otchestvo] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'and [Dolgnost]='Администратор'", connection);
                        opisanie[2] = command2.ExecuteScalar().ToString();
                        Admin.othestvo = $"{opisanie[2]}";    
                    }
                    using (Admin fd = new Admin())
                    {

                        this.Hide();
                        fd.ShowDialog();
                        this.Close();
                    }
                }
                if (checkOperator(textBox1.Text, textBox2.Text))
                {
                  
                    Operator nh = new Operator();
                    string[] opisanie = new string[3];
                    using (SqlConnection connection = new SqlConnection("server=ngknn.ru;Trusted_Connection=No;DataBase=31P_Trifonova_PP;User ID=31П;PWD=12357"))
                    {
                        connection.Open();
                        SqlCommand command = new SqlCommand("Select [Familia] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                        opisanie[0] = command.ExecuteScalar().ToString();
                        Operator.familia = $"{opisanie[0]}";

                        SqlCommand command1 = new SqlCommand("Select [Ima] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                        opisanie[1] = command1.ExecuteScalar().ToString();
                        Operator.ima = $"{opisanie[1]}";

                        SqlCommand command2 = new SqlCommand("Select [Otchestvo] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                        opisanie[2] = command2.ExecuteScalar().ToString();
                        Operator.othestvo = $"{opisanie[2]}";

                    }
                    using (Operator fd = new Operator())
                    {

                        this.Hide();
                        fd.ShowDialog();
                        this.Close();
                    }
                }
                if (checkSotr(textBox1.Text, textBox2.Text))
                {

                    
                       Zakaz nd = new Zakaz();
                    string[] opisanie = new string[7];
                   
                    using (SqlConnection connection = new SqlConnection("server=ngknn.ru;Trusted_Connection=No;DataBase=31P_Trifonova_PP;User ID=31П;PWD=12357"))
                    {
                        connection.Open();
                        SqlCommand command = new SqlCommand("Select [Familia] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                        opisanie[0] = command.ExecuteScalar().ToString();
                        Zakaz.familia = $"{opisanie[0]}";

                        SqlCommand command1 = new SqlCommand("Select [Ima] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                        opisanie[1] = command1.ExecuteScalar().ToString();
                        Zakaz.ima = $"{opisanie[1]}";

                        SqlCommand command2 = new SqlCommand("Select [Otchestvo] From [dbo].[Sotrudnik] where [Login] ='" + textBox1.Text + "' and [Password] ='" + textBox2.Text + "'", connection);
                        opisanie[2] = command2.ExecuteScalar().ToString();
                        Zakaz.othestvo = $"{opisanie[2]}";
                    }
                    using (Zakaz fd = new Zakaz())
                    {

                        this.Hide();
                        fd.ShowDialog();
                        this.Close();
                    }
                }
            }
        }
        
    }
}