PhotoStudio_PM_04/OrderForm.cs

using System;
using System.Data;
using System.Windows.Forms;
using Npgsql;

namespace PhotoStudioApp
{
    public partial class OrderForm : Form
    {
        private string _connectionString;
        private int? _orderId;

        public OrderForm(string connectionString, int? orderId = null)
        {
            InitializeComponent();
            _connectionString = connectionString;
            _orderId = orderId;

            LoadComboBoxes();

            if (_orderId.HasValue)
            {
                LoadOrderData();
            }
        }

        private void LoadComboBoxes()
        {
            using (NpgsqlConnection conn = new NpgsqlConnection(_connectionString))
            {
                conn.Open();

                // Загружаем клиентов
                string clientSql = "select client_id, last_name || ' ' || first_name as name from clients";
                NpgsqlDataAdapter clientAdapter = new NpgsqlDataAdapter(clientSql, conn);
                DataTable clientTable = new DataTable();
                clientAdapter.Fill(clientTable);
                cmbClient.DataSource = clientTable;
                cmbClient.DisplayMember = "name";
                cmbClient.ValueMember = "client_id";

                // Загружаем сотрудников
                string employeeSql = "select employee_id, last_name || ' ' || first_name as name from employees";
                NpgsqlDataAdapter employeeAdapter = new NpgsqlDataAdapter(employeeSql, conn);
                DataTable employeeTable = new DataTable();
                employeeAdapter.Fill(employeeTable);
                cmbEmployee.DataSource = employeeTable;
                cmbEmployee.DisplayMember = "name";
                cmbEmployee.ValueMember = "employee_id";

                // Загружаем услуги
                string serviceSql = "select service_id, service_name from services";
                NpgsqlDataAdapter serviceAdapter = new NpgsqlDataAdapter(serviceSql, conn);
                DataTable serviceTable = new DataTable();
                serviceAdapter.Fill(serviceTable);
                cmbService.DataSource = serviceTable;
                cmbService.DisplayMember = "service_name";
                cmbService.ValueMember = "service_id";
            }
        }

        private void LoadOrderData()
        {
            using (NpgsqlConnection conn = new NpgsqlConnection(_connectionString))
            {
                conn.Open();
                string sql = "select client_id, employee_id, service_id from orders where order_id = @orderId";
                NpgsqlCommand cmd = new NpgsqlCommand(sql, conn);
                cmd.Parameters.AddWithValue("@orderId", _orderId.Value);
                using (NpgsqlDataReader reader = cmd.ExecuteReader())
                {
                    if (reader.Read())
                    {
                        cmbClient.SelectedValue = reader["client_id"];
                        cmbEmployee.SelectedValue = reader["employee_id"];
                        cmbService.SelectedValue = reader["service_id"];
                    }
                }
            }
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            if (cmbClient.SelectedValue == null || cmbEmployee.SelectedValue == null || cmbService.SelectedValue == null)
            {
                MessageBox.Show("Выберите все поля");
                return;
            }

            int clientId = (int)cmbClient.SelectedValue;
            int employeeId = (int)cmbEmployee.SelectedValue;
            int serviceId = (int)cmbService.SelectedValue;

            using (NpgsqlConnection conn = new NpgsqlConnection(_connectionString))
            {
                conn.Open();
                string sql;
                if (_orderId.HasValue)
                {
                    sql = "update orders set client_id = @clientId, employee_id = @employeeId, service_id = @serviceId where order_id = @orderId";
                }
                else
                {
                    sql = "insert into orders (client_id, employee_id, service_id, order_date) values (@clientId, @employeeId, @serviceId, @orderDate)";
                }

                NpgsqlCommand cmd = new NpgsqlCommand(sql, conn);
                cmd.Parameters.AddWithValue("@clientId", clientId);
                cmd.Parameters.AddWithValue("@employeeId", employeeId);
                cmd.Parameters.AddWithValue("@serviceId", serviceId);

                if (_orderId.HasValue)
                {
                    cmd.Parameters.AddWithValue("@orderId", _orderId.Value);
                }
                else
                {
                    cmd.Parameters.AddWithValue("@orderDate", DateTime.Now);
                }

                cmd.ExecuteNonQuery();
                MessageBox.Show("Заказ сохранён");
                this.Close();
            }
        }

        private void btnCancel_Click(object sender, EventArgs e)
        {
            this.Close();
        }
    }
}