Styjun

I constantly write an error, the database is locked. I just can not understand why this is happening.
db_login.cs

private db_controller _dbctrl = new db_controller();
 public SqliteDataReader dataread;
 private string query;

//this two inputField, 
 public void LoginToGo()
 
 login = _login.captionText.text;
 pass = _pass.text.ToString();
 query = "SELECT id from users where users = '" + login + "' AND pass = '" + pass + "'";
 try
 
 dataread = _dbctrl.ExecuteReader(query);
 if(dataread.HasRows & dataread != null)
 
 while (dataread.Read())
 
 VerifyAdmin();
 _dbctrl.Disconnect();
 
 
 else
 
 errortxt.text = "Неверный логин или пароль, пожалуйста повторите!";
 
 
 catch (Exception ex) errortxt.text = ex.ToString(); 
 

 public void VerifyAdmin() //Who are you, admin or user
 
 login = _login.captionText.text;


 query_access = "SELECT root from users where users = '" + login + "'";
 try
 
 dataread = _dbctrl.ExecuteReader(query_access);
 while (dataread.Read())
 dataread[0].ToString() == null)
 
 MainMenu();

 
 else
 
 AdminMenu();

 
 

 
 catch (Exception ex) errortxt.text = ex.ToString(); 
 

 public void AdminMenu()
 
 JOIN.SetActive(false);
 ADMIN.SetActive(true);
 
 public void MainMenu()
 
 JOIN.SetActive(false);
 MAIN.SetActive(true);
 

db_controller.cs

public SqliteConnection con_db;
 public SqliteCommand cmd_db;
 public SqliteDataReader rdr_db;


public void connections()
 

 try
 

 if(Application.platform != RuntimePlatform.Android)
 
 path = Application.dataPath + "/StreamingAssets/db.bytes"; // Путь для Windows
 
 else
 
 path = Application.persistentDataPath + "/db.bytes"; // Путь для Android
 if(!File.Exists(path))
 

 WWW load = new WWW("jar:file://" + Application.dataPath + "!/assets/" + "db.bytes");
 while (!load.isDone) 
 File.WriteAllBytes(path, load.bytes);
 
 

 con_db = new SqliteConnection("URI=file:" + path);
 con_db.Open();
 if (con_db.State == ConnectionState.Open)
 

 debugText.text = path.ToString() + " - is connected";
 Debug.Log(path.ToString());

 

 
 catch (Exception ex)
 
 debugText.text = ex.ToString();
 
 

//Тут я создаю метод отключения
 public void Disconnect()
 

 con_db.Close();
 

 public SqliteDataReader ExecuteReader(string query)
 
 connections();
 try
 
 cmd_db = new SqliteCommand(query, con_db);
 rdr_db = cmd_db.ExecuteReader();
 return rdr_db;
 
 catch (Exception ex) debugText.text = ex.ToString(); return null; 
 

//Тут я записываю данные. Заодно решил проверить закрыто ли соединение.

 public void SetDB()
 

 if (con_db.State == ConnectionState.Open)
 
 Debug.Log("open");
 
 else
 
 Debug.Log("close!");
 
//The connection is closed. But I can not complete the request cmd_db.ExecuteNonQuery();
 connections();
 try
 
 brand = AutoName.captionText.text;
 model = AutoModel.captionText.text;
 years = OldAuto.captionText.text;
 number = GosNumber.text.ToString();
 nusers = UserName.text.ToString();
 dbirthday = DBirthday.captionText.text;
 mbirthday = MBirthday.captionText.text;
 ybirthday = YBirthday.captionText.text;
 mobile = Mobile.text.ToString();
 cmd_db = new SqliteCommand("INSERT INTO clients(brand,model,years,number,nusers,dbirthday,mbirthday,ybirthday,mobile,groupmodel) values('" + brand + "', '" + model + "','" + years + "','" + number + "','" + nusers + "','" + dbirthday + "','" + mbirthday + "','" + ybirthday + "','" + mobile + "','" +groupmodel+ "')" , con_db);
 cmd_db.ExecuteNonQuery(); //Swears, says that the base is locked. And why? I just read the data and the connection was closed.

 
 catch (Exception ex) debugText.text = ex.ToString(); 
 Disconnect();
 

the documentation says:
This error code occurs when you try to do two incompatible things with the database at the same time from the same connection to the database.

But the connection with the base is closed.
Maybe I'm missing something, or not doing the right thing. I ask for help to clarify this issue.