Spring Webflux - R2dbc :如何在迭代结果集时运行子查询和更新值

<dependencies>
    <!-- Spring Webflux -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-webflux</artifactId>
    </dependency>
    
    <!-- R2DBC -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-r2dbc</artifactId>
    </dependency>
    
    <!-- 具体的数据库驱动依赖，例如MySQL -->
    <dependency>
        <groupId>dev.miku</groupId>
        <artifactId>r2dbc-mysql</artifactId>
    </dependency>
</dependencies>

# 数据库连接配置
spring.r2dbc.url=r2dbc:mysql://localhost:3306/mydatabase
spring.r2dbc.username=username
spring.r2dbc.password=password

import org.springframework.data.repository.reactive.ReactiveCrudRepository;
import reactor.core.publisher.Flux;
import com.example.demo.User;

public interface UserRepository extends ReactiveCrudRepository<User, Long> {
    Flux<User> findByAgeGreaterThan(int age);
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.example.demo.User;
import com.example.demo.UserRepository;
import reactor.core.publisher.Flux;

@Service
public class UserService {
    private final UserRepository userRepository;
    
    @Autowired
    public UserService(UserRepository userRepository) {
        this.userRepository = userRepository;
    }
    
    public Flux<User> getUsersWithSubquery(int ageThreshold) {
        return userRepository.findByAgeGreaterThan(ageThreshold)
                .flatMap(this::executeSubqueryAndUpdateValue);
    }
    
    private Mono<User> executeSubqueryAndUpdateValue(User user) {
        // 执行子查询和更新值的操作
        // ...
        return Mono.just(user);
    }
}