Spring Data R2DBC中@Query注解与Flux参数的深度解析

public interface PersonRepository extends ReactiveCrudRepository<Person, Person> {

    @Query("SELECT id, name FROM Person WHERE id = ?")
    Flux<Person> myMethod(Flux<Person> person); // 尝试使用Flux作为参数

}

public interface PersonRepository extends ReactiveCrudRepository<Person, Long> { // 注意ID类型应与实体ID类型匹配

    // Spring Data会自动根据方法名生成查询，支持Flux/Publisher参数
    Flux<Person> findAllByIdIn(Flux<Long> ids); // 或者直接使用 findAllById(Publisher<Long> ids)

    // 也可以根据其他字段进行批量查询
    Flux<Person> findAllByNameIn(Flux<String> names);

    // 对于单个字段的精确匹配，也可以这样定义
    Flux<Person> findAllByName(Flux<String> names);
}

import lombok.*;
import org.springframework.data.annotation.Id;
import org.springframework.data.relational.core.mapping.Column;
import org.springframework.data.relational.core.mapping.Table;
import reactor.core.publisher.Flux; // 引入Flux

@Getter
@Setter
@ToString
@Data
@NoArgsConstructor
@AllArgsConstructor
@Table(value = "Person", schema = "mySchema")
public class Person {
    @Id
    @Column("id")
    Long id;

    @Column("name")
    String name;
}

import org.springframework.data.r2dbc.repository.ReactiveCrudRepository;
import reactor.core.publisher.Flux;

public interface PersonRepository extends ReactiveCrudRepository<Person, Long> {

    // 正确的用法：利用派生查询，无需@Query注解
    Flux<Person> findAllById(Flux<Long> idStream); // 效果等同于findAllByIdIn

    // 如果需要更具体的名称，也可以使用In关键字
    Flux<Person> findAllByIdIn(Flux<Long> idStream);

    // 根据名称批量查询
    Flux<Person> findAllByNameIn(Flux<String> names);
}

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import reactor.core.publisher.Flux;
import java.util.function.LongSupplier;
import java.util.stream.LongStream;
import org.apache.commons.lang3.RandomUtils; // 假设已引入此依赖

@SpringBootApplication
@EnableConfigurationProperties({ApplicationProperties.class}) // 替换为你的配置属性类
public class MyApplication {

    private static final Logger logger = LoggerFactory.getLogger(MyApplication.class);

    public static void main(String[] args) {
        SpringApplication.run(MyApplication.class, args);
    }

    @Bean
    public CommandLineRunner consume(PersonRepository personRepository) {
        return args -> {
            LongSupplier randomLong = () -> RandomUtils.nextLong(1L, 10L); // 假设ID范围为1-10

            Flux<Long> personIds = Flux.fromStream(LongStream.generate(randomLong).boxed()).take(3);

            logger.info("Generated Person IDs to query: " + personIds.collectList().block()); // 打印生成的ID

            // 使用派生查询方法，传入Flux参数
            personRepository.findAllById(personIds)
                .doOnNext(person -> logger.info("Processed Person: " + person))
                .doOnError(e -> logger.error("Error during processing: " + e.getMessage(), e))
                .doOnComplete(() -> logger.info("All persons processed."))
                .subscribe(); // 订阅以触发执行

            // 确保应用程序不会立即退出，以便观察异步结果
            Thread.sleep(2000); // 生产环境中不推荐，仅为示例演示
        };
    }
}