bazeLV7

using System;
using System.Data;
using System.Data.SqlClient;
using System.Windows.Forms;

public partial class Form1 : Form
{
    private int? selectedPersonId = null;

    public Form1()
    {
        InitializeComponent();
        this.dgvPodaci.SelectionChanged += new System.EventHandler(this.dgvPodaci_SelectionChanged);
        this.btnBrisi.Click += new System.EventHandler(this.btnBrisi_Click);
        this.btnPrikaziSve.Click += new System.EventHandler(this.btnPrikaziSve_Click);
        this.btnSpremi.Click += new System.EventHandler(this.btnSpremi_Click);
    }

    private void PrikaziSveOsobe()
    {
        string connectionString = "Server=xxx.xxx.xxx.xxx;Database=student;User Id=student;Password=student;";
        string query = "SELECT * FROM osobe ORDER BY prezime";

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            SqlDataAdapter dataAdapter = new SqlDataAdapter(query, connection);
            DataTable dataTable = new DataTable();
            dataAdapter.Fill(dataTable);
            dgvPodaci.DataSource = dataTable;
        }
    }

    private void dgvPodaci_SelectionChanged(object sender, EventArgs e)
    {
        if (dgvPodaci.SelectedRows.Count > 0)
        {
            DataGridViewRow selectedRow = dgvPodaci.SelectedRows[0];
            selectedPersonId = Convert.ToInt32(selectedRow.Cells["id"].Value);
            txtOIB.Text = selectedRow.Cells["OIB"].Value.ToString();
            txtIme.Text = selectedRow.Cells["ime"].Value.ToString();
            txtPrezime.Text = selectedRow.Cells["prezime"].Value.ToString();
            txtDatum.Text = Convert.ToDateTime(selectedRow.Cells["datum_rodenja"].Value).ToString("dd.MM.yyyy");
            if (selectedRow.Cells["spol"].Value.ToString() == "M")
            {
                rbM.Checked = true;
            }
            else
            {
                rbZ.Checked = true;
            }
            txtVisina.Text = selectedRow.Cells["visina"].Value.ToString();
            txtBrCip.Text = selectedRow.Cells["broj_cipela"].Value.ToString();

            btnBrisi.Enabled = true;
        }
        else
        {
            btnBrisi.Enabled = false;
        }
    }

    private void SpremiOsobu()
    {
        string connectionString = "Server=xxx.xxx.xxx.xxx;Database=student;User Id=student;Password=student;";
        string query;

        if (selectedPersonId == null)
        {
            query = "INSERT INTO osobe (OIB, ime, prezime, datum_rodenja, spol, visina, broj_cipela) " +
                    "VALUES (@OIB, @Ime, @Prezime, @DatumRodenja, @Spol, @Visina, @BrojCipela)";
        }
        else
        {
            query = "UPDATE osobe SET OIB = @OIB, ime = @Ime, prezime = @Prezime, datum_rodenja = @DatumRodenja, " +
                    "spol = @Spol, visina = @Visina, broj_cipela = @BrojCipela WHERE id = @Id";
        }

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            using (SqlCommand command = new SqlCommand(query, connection))
            {
                command.Parameters.AddWithValue("@OIB", txtOIB.Text);
                command.Parameters.AddWithValue("@Ime", txtIme.Text);
                command.Parameters.AddWithValue("@Prezime", txtPrezime.Text);
                command.Parameters.AddWithValue("@DatumRodenja", DateTime.Parse(txtDatum.Text));
                command.Parameters.AddWithValue("@Spol", rbM.Checked ? "M" : "Z");
                command.Parameters.AddWithValue("@Visina", int.Parse(txtVisina.Text));
                command.Parameters.AddWithValue("@BrojCipela", int.Parse(txtBrCip.Text));

                if (selectedPersonId != null)
                {
                    command.Parameters.AddWithValue("@Id", selectedPersonId);
                }

                connection.Open();
                command.ExecuteNonQuery();
            }
        }

        selectedPersonId = null;
        ClearFormFields();
        btnBrisi.Enabled = false;
        PrikaziSveOsobe();
    }

    private void BrisiOsobu()
    {
        if (selectedPersonId == null)
        {
            MessageBox.Show("Nije odabrana nijedna osoba za brisanje.");
            return;
        }

        string connectionString = "Server=xxx.xxx.xxx.xxx;Database=student;User Id=student;Password=student;";
        string query = "DELETE FROM osobe WHERE id = @Id";

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            using (SqlCommand command = new SqlCommand(query, connection))
            {
                command.Parameters.AddWithValue("@Id", selectedPersonId);

                connection.Open();
                command.ExecuteNonQuery();
            }
        }

        selectedPersonId = null;
        ClearFormFields();
        btnBrisi.Enabled = false;
        PrikaziSveOsobe();
    }

    private void ClearFormFields()
    {
        txtOIB.Clear();
        txtIme.Clear();
        txtPrezime.Clear();
        txtDatum.Clear();
        rbM.Checked = false;
        rbZ.Checked = false;
        txtVisina.Clear();
        txtBrCip.Clear();
    }

    private void btnPrikaziSve_Click(object sender, EventArgs e)
    {
        PrikaziSveOsobe();
    }

    private void btnSpremi_Click(object sender, EventArgs e)
    {
        SpremiOsobu();
    }

    private void btnBrisi_Click(object sender, EventArgs e)
    {
        BrisiOsobu();
    }
}