File indexing completed on 2024-12-08 12:44:36

 // SPDX-FileCopyrightText: 2022 Jonah Brüchert <jbb@kaidan.im
 //
 // SPDX-License-Identifier: BSD-2-Clause
 
 /*
  * This example demonstrates how to use transactions with FutureSQL
  * For explanations of the general concepts, see the hello-world example,
  * which is very similar (except it doesn't use transactions, of course),
  * but it contains more comments.
  */
 
 // Qt
 #include <QCoreApplication>
 #include <QTimer>
 
 // QCoro
 #include <QCoro/QCoroTask>
 #include <QCoro/QCoroFuture>
 
 // FutureSQL
 #include <ThreadedDatabase>
 
 // STL
 #include <tuple>
 
 // Why is this function not part of the library, I hear you ask.
 // Currently, FutureSQL should not hard-depend on QCoro,
 // even though with Qt5, QCoro is the only way to use it without
 // hand-crafting helper functions to deal with QFutures.
 template <typename Func>
 QCoro::Task<> transaction(std::unique_ptr<ThreadedDatabase> &database, Func queryFunc) {
     co_await database->execute(QStringLiteral("BEGIN TRANSACTION"));
     co_await queryFunc();
     co_await database->execute(QStringLiteral("COMMIT"));
 }
 
 struct HelloWorld {
     using ColumnTypes = std::tuple<int, QString>;
 
     // attributes
     int id;
     QString data;
 };
 
 QCoro::Task<> databaseExample() {
     // This object contains the database configuration,
     // in this case just the path to the SQLite file, and the database type (SQLite).
     DatabaseConfiguration config;
     config.setDatabaseName(QStringLiteral("database.sqlite"));
     config.setType(DatabaseType::SQLite);
 
     // Here we open the database file, and get a handle to the database.
     auto database = ThreadedDatabase::establishConnection(config);
 
     // Run the following steps in a transaction
     co_await transaction(database, [&database]() -> QCoro::Task<> {
         // Create the table
         co_await database->execute(QStringLiteral("CREATE TABLE IF NOT EXISTS test (id INTEGER PRIMARY KEY AUTOINCREMENT, data TEXT)"));
 
         // Insert some initial data
         co_await database->execute(QStringLiteral("INSERT INTO test (data) VALUES (?)"), QStringLiteral("Hello World"));
     });
 
     // Retrieve some data from the database.
     // The data is directly returned as our HelloWorld struct.
     auto results = co_await database->getResults<HelloWorld>(QStringLiteral("SELECT * FROM test"));
 
     // Print out the data in the result list
     for (const auto &result : results) {
         qDebug() << result.id << result.data;
     }
 
     // Quit the event loop as we are done
     QCoreApplication::instance()->quit();
 }
 
 // Just a minimal main function for QCoro, to start the Qt event loop.
 int main(int argc, char *argv[]) {
     QCoreApplication app(argc, argv);
     QTimer::singleShot(0, databaseExample);
     return app.exec();
 }