fixed some heavy pointermistakes

database.cpp

@@ -13,6 +13,12 @@ DataBase::DataBase()
     this->db->setDatabaseName("Renndatenbank.sqlite");
     std::cout << "Konstruktor Database" << std::endl;
 }
+DataBase::~DataBase(){
+    std::cout << "Destruktor aus Datenbank" << std::endl;
+    delete this->db;
+    //delete this;
+}
+
 vector< vector<QString> > DataBase::getData2(std::string statement, int cols){
 
     vector<QString> data;