Tutorial CRUD C# Sederhana dengan MySql – Studi Kasus Pendataan Nilai Siswa

public MySqlCommand cmd;
public MySqlDataReader dr;
public String id;

private void Tampil()
{
    try
    {
      

Koneksi.conn.Open(); 

MySqlDataAdapter da = new MySqlDataAdapter("SELECT * FROM `vmapel`", Koneksi.conn);

DataSet ds = new DataSet();

da.Fill(ds);

dgsiswa.DataSource = ds.Tables[0];
Koneksi.conn.Close();
    }
    catch (Exception)
    {

MessageBox.Show("Duh!!, Ada Error Nih");
    }
}

Tampil();
MySqlDataAdapter adp = new MySqlDataAdapter("select * from guru", Koneksi.conn);
DataTable dt = new DataTable();
adp.Fill(dt);

cbnamaguru.DataSource = dt;
cbnamaguru.DisplayMember = "nama";
cbnamaguru.ValueMember = "id";

private void Clear()
{
    
  txtnama.Text = "";
  txtkodemapel.Text = "";
  txtcari.Text="";
  cbnamaguru.Text = "";

  btDelete.Enabled = false;
  btUpdate.Enabled = false;
  btCancel.Enabled = false;
  btInsert.Enabled = true;

}

try
{
    Koneksi.conn.Open();
    String Queri = "INSERT INTO mapel (`nama_mapel`, `kode_mapel`, `guru_id`) VALUES ('" + txtnamamapel.Text + "', '" + txtkodemapel.Text + "', '" + cbnamaguru.SelectedValue + "')";
    cmd = new MySqlCommand(Queri, Koneksi.conn);
    cmd.ExecuteNonQuery();
    MessageBox.Show("Berhasil Simpan Data Mapel");
    Koneksi.conn.Close();

    Tampil();
    Clear();
}
catch (Exception)
{

    MessageBox.Show("Tambah Data Gagal");
}
        }

btDelete.Enabled = true;
btUpdate.Enabled = true;
btCancel.Enabled = true;
btInsert.Enabled = false;

int baris = dgmapel.CurrentCell.RowIndex;
id = dgmapel.Rows[baris].Cells[0].Value.ToString();
txtnamamapel.Text = dgmapel.Rows[baris].Cells[1].Value.ToString();
txtkodemapel.Text = dgmapel.Rows[baris].Cells[2].Value.ToString();
cbnamaguru.Text = dgmapel.Rows[baris].Cells[3].Value.ToString();

try
{
    Koneksi.conn.Open();
    String Queri = "UPDATE mapel SET `nama_mapel`='" + txtnamamapel.Text + "', `kode_mapel`='" + txtkodemapel.Text+ "', `guru_id`='" + cbnamaguru.SelectedValue + "' WHERE  `id`='" + id + "'";
    cmd = new MySqlCommand(Queri, Koneksi.conn);
    cmd.ExecuteNonQuery();
    MessageBox.Show("Berhasil Update Data Guru");
    Koneksi.conn.Close();

    Tampil();
    Clear();
}
catch (Exception)
{

    MessageBox.Show("Update Gagal");
}

try
 {
     Koneksi.conn.Open();


     cmd = new MySqlCommand("DELETE FROM mapel WHERE  `id`= '" + id + "'", Koneksi.conn);
     cmd.ExecuteNonQuery();
     MessageBox.Show("Berhasil Hapus Data mapel");
     Koneksi.conn.Close();

     Tampil();
     Clear();
 }
 catch (Exception)
 {

     MessageBox.Show("Hapus Data Gagal");
 }

Clear();

try
{

    Koneksi.conn.Open();
    MySqlDataAdapter da = new MySqlDataAdapter("SELECT * FROM `vmapel` where nama_mapel LIKE '%" + txtcari.Text + "%'", Koneksi.conn);
    DataSet ds = new DataSet();

    da.Fill(ds);
    dgmapel.DataSource = ds.Tables[0];
    Koneksi.conn.Close();
}
catch (Exception)
{

    MessageBox.Show("Duh!!, Ada Error Nih");
}