browser.cpp Example File
^{demos/sqlbrowser/browser.cpp}

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    ** This file is part of the documentation of the Qt Toolkit.
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    #include "browser.h"
    #include "qsqlconnectiondialog.h"

    #include <QtGui>
    #include <QtSql>

    Browser::Browser(QWidget *parent)
        : QWidget(parent)
    {
        setupUi(this);

        if (QSqlDatabase::drivers().isEmpty())
            QMessageBox::information(this, tr("No database drivers found"),
                                     tr("This demo requires at least one Qt database driver. "
                                        "Please check the documentation how to build the "
                                        "Qt SQL plugins."));
        else {
            QMetaObject::invokeMethod(this, "addConnection", Qt::QueuedConnection);
        }

        emit statusMessage(tr("Ready."));
    }

    Browser::~Browser()
    {
    }

    void Browser::exec()
    {
        QSqlQueryModel *model = new QSqlQueryModel(table);
        model->setQuery(QSqlQuery(sqlEdit->toPlainText(), connectionWidget->currentDatabase()));
        table->setModel(model);

        if (model->lastError().type() != QSqlError::NoError)
            emit statusMessage(model->lastError().text());
        else if (model->query().isSelect())
            emit statusMessage(tr("Query OK."));
        else
            emit statusMessage(tr("Query OK, number of affected rows: %1").arg(
                        model->query().numRowsAffected()));
    }

    void Browser::addConnection()
    {
        QSqlConnectionDialog dialog(this);
        if (dialog.exec() != QDialog::Accepted)
            return;

        if (dialog.useInMemoryDatabase()) {
            QSqlDatabase::database("in_mem_db", false).close();
            QSqlDatabase::removeDatabase("in_mem_db");
            QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE", "in_mem_db");
            db.setDatabaseName(":memory:");
            if (!db.open())
                QMessageBox::warning(this, tr("Unable to open database"), tr("An error occured while "
                                                                             "opening the connection: ") + db.lastError().text());
            QSqlQuery q("", db);
            q.exec("drop table Movies");
            q.exec("drop table Names");
            q.exec("create table Movies (id int primary key, Title varchar(50), Director varchar(20), Rating number(2,2))");
            q.exec("insert into Movies values (0, 'Metropolis', 'Fritz Lang', '8.4')");
            q.exec("insert into Movies values (1, 'Nosferatu, eine Symphonie des Grauens', 'F.W. Murnau', '8.1')");
            q.exec("insert into Movies values (2, 'Bis ans Ende der Welt', 'Wim Wenders', '6.5')");
            q.exec("insert into Movies values (3, 'Hardware', 'Richard Stanley', '5.2')");
            q.exec("insert into Movies values (4, 'Mitchell', 'Andrew V. McLaglen', '2.1')");
            q.exec("create table Names (id int primary key, Firstname varchar(20), Lastname varchar(20), City varchar(20))");
            q.exec("insert into Names values (0, 'Sala', 'Palmer', 'Morristown')");
            q.exec("insert into Names values (1, 'Christopher', 'Walker', 'Morristown')");
            q.exec("insert into Names values (2, 'Donald', 'Duck', 'Andeby')");
            q.exec("insert into Names values (3, 'Buck', 'Rogers', 'Paris')");
            q.exec("insert into Names values (4, 'Sherlock', 'Holmes', 'London')");
        } else {
            static int cCount = 0;
            QSqlDatabase db = QSqlDatabase::addDatabase(dialog.driverName(),
                                                        QString("Browser%1").arg(++cCount));
            db.setDatabaseName(dialog.databaseName());
            db.setHostName(dialog.hostName());
            db.setUserName(dialog.userName());
            db.setPassword(dialog.password());
            db.setPort(dialog.port());
            if (!db.open())
                QMessageBox::warning(this, tr("Unable to open database"), tr("An error occured while "
                                                                             "opening the connection: ") + db.lastError().text());
        }
        connectionWidget->refresh();
    }

    void Browser::showTable(const QString &t)
    {
        QSqlTableModel *model = new QSqlTableModel(table, connectionWidget->currentDatabase());
        model->setTable(t);
        model->select();
        if (model->lastError().type() != QSqlError::NoError)
            emit statusMessage(model->lastError().text());
        table->setModel(model);
    }