How to update QTableView when database updated?

问题

I use QSqlRelationalTableModel to extract data from database, and use tableView to show it. Now, when I update my database, how to update tableView automatically to show it? I know i need to use function dataChanged() to make this automatically, but i do not know how to use it? Any suggestion will be appreciated.

The main code is as follows:

QSqlRelationalTableModel *model = new QSqlRelationalTableModel(NULL, db);
model->setTable(tableName);
model->select();
tableView->setModel(model);
tableView->show();

回答1:

No, there is no need to use dataChanged().

You just need to call QSqlRelationalTableModel::select() whenever the database gets updated. This will re-populate the model from the database, and update the views that are using it automatically.

• If the database is updated from within you application, you can just call model->select() after the update queries get executed in your application.

• If the database is updated from another application, you'll have to use something like PostgreSQL's event notification system, subscribe to the notification from your application using QSqlDriver::subscribeToNotification() and call model->select() in a slot connected to the notification() signal.

  You can use QSqlDriver::hasFeature(QSqlDriver::EventNotifications) to check if notifications from your database are supported.

来源：https://stackoverflow.com/questions/40188267/how-to-update-qtableview-when-database-updated