I am beginner in mysql why i am getting this error? :     if (comboBox2.Text == "A")
                        {
                            baglanti.Open();
                            cmd = new MySqlCommand("SELECT `Sifreler`FROM `9sinifgiris` WHERE 1", baglanti);
                           
                            dr = cmd.ExecuteReader(); 
                            if (dr.Read()) // Veriyi çektik
                            {
                                if (textBox1.Text == dr["Sifreler"].ToString()) 
                                { baglanti.Close();
                                    MessageBox.Show("Parola aynı giriş yap");
                                    button1.Enabled = true;
                                    baglanti.Open();
                                    cmd = new MySqlCommand("insert into 9sinifgiris (9A) Values ('TestText')", baglanti);
                                    cmd.ExecuteNonQuery(); // GETTİNG ERROR FROM HERE 
                                }
                                else { MessageBox.Show("Parola yanlış"); textBox1.Clear(); }
                            }
                            baglanti.Close();

*And im getting error from  cmd.ExecuteNonQuery(); <<-- here 
 I used to work with this code for my old project and it worked well. I want to add text in database what i write. 
**MySql.Data.MySqlClient.MySqlException: 'Field 'Sifreler' doesn't have a default value'**
 This is what error says 
 I don't want to fill **Sifreler** this line in database but error shows me this line 
My english not so good i hope i can explain my problem and all you guys/ladies can help me.*