Russian Qt Forum

main.cpp

#include <QApplication>
#include "qmywidget.h"

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QMyWidget wgt(0);
    return app.exec();
}

qmywidget.h

#ifndef QMYWIDGET_H
#define QMYWIDGET_H

#include <QWidget>

class QPlainTextEdit;
class QPushButton;
class QVBoxLayout;

class QMyWidget : public QWidget
{
    Q_OBJECT

protected:
    virtual void closeEvent(QCloseEvent*);

public:
    QMyWidget(QWidget * = 0);
    QPlainTextEdit *pTE;
    QPushButton *cmdNotify;
    QVBoxLayout *layout;

public slots:
    void slotNotify();
    void slotNotification(const QString &);

};

#endif // QMYWIDGET_H


qmywidget.cpp

#include <QPlainTextEdit>
#include <QPushButton>
#include <QtSql>
#include <QVBoxLayout>
#include "qmywidget.h"

QMyWidget::QMyWidget(QWidget *parent) : QWidget(parent)
{
    pTE = new QPlainTextEdit(this);
    cmdNotify = new QPushButton("Notify", this);
    layout = new QVBoxLayout();
    layout->addWidget(pTE);
    layout->addWidget(cmdNotify);
    setLayout(layout);

    QSqlDatabase db = QSqlDatabase::addDatabase("QPSQL7");
    db.setDatabaseName("test");
    db.setHostName("localhost");
    db.setPort(***);
    db.setUserName(***);
    db.setPassword(***);
    if (!db.open()) {
      qDebug() << "Database opened: " << db.lastError();
    }
    else { qDebug() << "Database error";}

    db.driver()->subscribeToNotification("n1");
    connect(db.driver(), SIGNAL(notification(const QString&)), this, SLOT(slotNotification(const QString&)) );
    connect(cmdNotify, SIGNAL(clicked()), this, SLOT(slotNotify()));
    show();
}

void QMyWidget::slotNotification(const QString &Notif) {
    pTE->appendPlainText(Notif);
}

void QMyWidget::slotNotify() {
    pTE->appendPlainText("Notify button pressed");
    QSqlQuery queryNotify("NOTIFY n1;");
}

void QMyWidget::closeEvent(QCloseEvent *event) {
    QSqlDatabase db = QSqlDatabase::database();
    if (db.isOpen()) { db.close(); }
}

CREATE TRIGGER name_of_trigger FOR some_table
AFTER UPDATE AS
BEGIN
  NOTIFY n1;
END 

CREATE TRIGER trigg AFTER UPDATE ON table1 AS
BEGIN
     NOTIFY n1;
END