How to return a Flux of a DTO when fetching child records of a collection?-CodePudding

I'm trying to basically do nested loops with reactive/spring webflux. How would I go about iterating through a Flux, fetching child records, and ultimately return a Flux of DTOs (with the child records in each user dto)?

Here's the gist of it, although probably still way off.

public Flux<UserDTO> getUsers(String name) {
     Flux<User> users = userRepo.findByNameLike(name);
     
     return users.flatMap(u -> {
            Flux<Phone> phoneNumbers = phoneNumberRepo.findByUserId(u.getUserId());
            
            return phoneNumbers;
       }).flatMap(r -> {
            UserDto userDto = new UserDto();
            userDto.setUserId(u.getUserid());
            userDto.setPhoneNumbers(phoneNumbers);
            
            return userDto;
       });
}

CodePudding user response：

you need to use map instead of flatMap on transfer to dto

CodePudding user response：

You should collect the child entities to list before mapping.

    public Flux<UserDto> getUsers(String name) {
        Flux<User> users = userRepo.findByNameLike(name);

        return users.flatMap(u -> phoneNumberRepo.findByUserId(u.getUserId())
                .collectList()
                .map(phoneNumbers -> {
                    UserDto userDto = new UserDto();
                    userDto.setUserId(u.getUserId());
                    userDto.setPhoneNumbers(phoneNumbers);
                    return userDto;
                }));
    }