Spring Boot Get Value of object from select using thymeleaf - spring

Question

So I have this project, and I want to return an object, from the previous choice of 2 select items. How can I do it? for example:
<select class="form-control" id="cityPicker1">
<option value="0">select option</option>
<option th:each="city: ${listCities}" th:value="${city.number}" th:text="${city.name}"></option>
</select>
<select class="form-control" id="cityPicker2">
<option value="0">select option</option>
<option th:each="city: ${listCities}" th:value="${city.number}" th:text="${city.name}"></option>
</select>
I want to display an item from another item list which has a number1 field and a number2 something like ticket.number1 and ticket.number2 but they have to match the values from the previous selects. I can't seem to find anything. Any ideas?
This is how I set it up in the controller:
#GetMapping("/tickets")
public String viewTicketsPage(Model model) {
List<City> listCities = cityRepo.findAll();
List<Ticket> listTickets = ticketRepo.findAll();
model.addAttribute("listCities", listCities);
model.addAttribute("listTickets", listTickets);
return "tickets";
}

Answer 1

I need to clarify a few things about your question.
1 - did you manage to get the checkboxes to work?
2 - can you send the selected data to the controller?
you need a controller to receive data from the page, send this data to the repository to fetch other data..
I believe you want to select a table, where the data matches the selected ones. .
take a look at JPQL, maybe this will help you:
https://www.baeldung.com/spring-data-jpa-query