Пересматриваем решение на счёт SQL

src/database/databasemanager.h

@@ -0,0 +1,21 @@
+#ifndef DATABASEMANAGER_H
+#define DATABASEMANAGER_H
+
+#include <QDebug>
+#include <QtSql>
+
+class Q_DECL_EXPORT DatabaseManager
+{
+public:
+    static DatabaseManager& instance();
+    bool connect(const QString& dbPath);
+    QSqlDatabase& database();
+    void initializeDatabase();
+
+private:
+    DatabaseManager();
+    ~DatabaseManager();
+    QSqlDatabase db;
+};
+
+#endif // DATABASEMANAGER_H