我正在使用 hibernate ，寻找最佳实践以避免在数据库中进行相同的插入。我编写了程序，根据用户输入保存来自 API 的搜索结果，当输入相同时，我在数据库中复制了没有 id 的行。这对我来说是个问题，因为在未来的使用中。 每个插入必须是唯一的。
实体模型的一部分:
@Entity
@Component
public class Flight {
private Long id;
private String departure;
private String currency;
private String destination;
private BigDecimal price;
... etc //
保存代码:
@RequestMapping(value = "/save", method = RequestMethod.GET)
public String save(
@ModelAttribute("FlightDTO") FlightDTO flightDTO,
@ModelAttribute("FlightOutput") Map<String, Map<String, FlightDeserialization>> flightOutputMap,
@ModelAttribute("HotelOutput") ArrayList<Comparison> hotelOutputList,
@ModelAttribute("HotelGooglePlaceList") Map<Integer, List<PlacesResults>> hotelGooglePlaceList,
@ModelAttribute("HotelGoogleImageList") Map<Integer, List<Imageresults>> hotelGoogleImageList) {
boolean isHotelGoogleListEqualToHotelOutputList = hotelGooglePlaceList.keySet().size() == hotelOutputList.size() & hotelGooglePlaceList.keySet().size() == hotelGoogleImageList.size();
Flight flight;
for (String keyOut : flightOutputMap.keySet()) {
for (String keyIn : flightOutputMap.get(keyOut).keySet()) {
flight = new Flight();
flight.setCurrency(flightDTO.getCurrency());
flight.setAirline(csvParser.airlineParser(flightOutputMap.get(keyOut).get(keyIn).getAirline()));
flight.setAirlineIata(flightOutputMap.get(keyOut).get(keyIn).getAirline());
flight.setDepartureTime(flightOutputMap.get(keyOut).get(keyIn).getDepartureTime());
flight.setReturnTime(flightOutputMap.get(keyOut).get(keyIn).getReturnTime());
flight.setFlightNumber(flightOutputMap.get(keyOut).get(keyIn).getFlightNumber());
flight.setPrice(flightOutputMap.get(keyOut).get(keyIn).getPrice());
flight.setExpiresAt(flightOutputMap.get(keyOut).get(keyIn).getExpiresAt());
flight.setDestination(flightDTO.getDestination());
flight.setDeparture(flightDTO.getDeparture());
flight.setUserName(CurrentUserName().getUsername());
if (isHotelGoogleListEqualToHotelOutputList) {
Hotel hotel;
BigDecimal exchangeRate = currencyRepository.findByName(flightDTO.getCurrency()).getExchangeRate();
for (int i = 0; i < hotelOutputList.size(); i++) {
Comparison array = hotelOutputList.get(i);
hotel = new Hotel();
hotel.setImage(hotelGoogleImageList.get(i).get(1).getImage());
hotel.setHotelLink(hotelGoogleImageList.get(i).get(0).getLink());
hotel.setLatitude(hotelGooglePlaceList.get(i).get(0).getGps_coordinates().getLatitude());
hotel.setLongitude(hotelGooglePlaceList.get(i).get(0).getGps_coordinates().getLongitude());
hotel.setCurrency(flightDTO.getCurrency());
hotel.setName(array.getHotel());
hotel.setSite(array.getVendor1());
hotel.setSite(array.getVendor2());
hotel.setPrice(hotelCurrencyService.amountCalculator(array.getVendor1Price(), exchangeRate));
hotel.setPrice(hotelCurrencyService.amountCalculator(array.getVendor2Price(), exchangeRate));
hotel.setPrice(hotelCurrencyService.amountCalculator(array.getVendor3Price(), exchangeRate));
flight.setHotel(hotel);
flightRepository.save(flight);
我尝试过使用 @UniqueConstraint 和 @Unique，但我猜它是用于其他用途。
请帮助我!
最佳答案
首先，您的实体上不需要 @Component。
二、添加这个注解
@Table(name = "table_name", uniqueConstraints={@UniqueConstraint(columnNames ={"id", "departure", ...})})
包含不应重复的字段。
注意:您需要将 spring.jpa.hibernate.ddl-auto=update 添加到 application.properties
关于java - 防止数据库中重复行的最佳方法，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/57238457/