How Can I use db in threads? Requested database does not belong to the calling thread.

Subuday

How to use database in threads? I create instance of db in main thread and give threads pointers. But it crashes, also I tried to create instance in Thread, it doesn't work. How Can I use db in threads?

#ifndef THREAD_H
#define THREAD_H

#include <QThread>
#include <QTcpSocket>
#include <QRegularExpression>

#include "dbmanager.h"

class MyThread : public QThread
{
  Q_OBJECT

  public:
    explicit MyThread(qintptr ID, QObject *parent = nullptr);
    ~MyThread();

    void run();

  signals:
    void error(QTcpSocket::SocketError socketerror);

  public slots:
    void readyRead();
    void disconnected();

  private:
    QTcpSocket *socket;
    qintptr socketDescriptor;

    DB_Manager * db;

    void analysis(QString httpRequest, QString& method, QString& uri, QString& body);
};

#endif // THREAD_H

void MyThread::run()
{
  socket = new QTcpSocket();

  if (!socket->setSocketDescriptor(this->socketDescriptor) )
  {
    emit error (socket->error());
    return;
  }

  connect(socket, SIGNAL(readyRead()), this, SLOT(readyRead()),Qt::DirectConnection );
  connect(socket, SIGNAL(disconnected()), this, SLOT(disconnected()));

  exec();
}

void HttpServer::incomingConnection(qintptr socketDescriptor)
{
    MyThread *thread = new MyThread(socketDescriptor, this);
    connect(thread, SIGNAL(finished()), thread, SLOT(deleteLater()));

    thread->start();
}

In MyThread function:

QJsonDocument dbody = QJsonDocument::fromJson(body.toLocal8Bit());
            QString password = dbody.object()["password"].toString();

            int id = db->getIdByLog(tname.toStdString(), password.toStdString());

            if(id != 0)
            {
                sendLog(true, id);
            }
            else
            {
                sendLog(false, 0);
            }

SGaist

Hi,

What is DB_Manager ?
Where do you allocate it ?
How is it implemented ?