kubsu-sm4-db-lab-win-forms/db_lab/RaportForm.cs

using Npgsql;
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;

namespace db_lab
{
    public partial class RaportForm : Form
    {
        NpgsqlConnection connection;

        private void load_data()
        {
            try
            {
                connection.Open();
                string sql = @"SELECT
    ead.id AS interaction_id,
    e.name AS equipment_name,
    r.room_name AS room_name,
    d.name AS department_name,
    b.address AS building_address,
    ead.arrival_date,
    ead.departure_date
FROM Equipment_Arrival_Departure ead
JOIN Equipment e ON ead.equipment_id = e.id
JOIN Rooms r ON e.room_id = r.id
JOIN Department d ON r.building_id = d.building_id
JOIN Building b ON d.building_id = b.id;
";
                NpgsqlDataAdapter adapter = new NpgsqlDataAdapter(sql, this.connection);
                DataSet dataset = new DataSet();
                adapter.Fill(dataset, "data");
                dataGridView1.DataSource = dataset.Tables["data"];
                connection.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show($"Error! Log: {ex.Message}");
                connection.Close();
            }
        }

        public RaportForm(string connection)
        {
            this.connection = new NpgsqlConnection(connection);
            InitializeComponent();
            load_data();
        }
    }
}