<Spring Boot / Hibernate> 插入前删除未完成

Question

您好，我正在使用 Spring Boot hibernate 在 MySQL 中测试记录 delete-insert-delete 操作，我注意到一个问题，即插入发生时似乎没有完全删除记录。

在 hibernate kickstart 上创建 3 个初始记录（通过类路径中的 data.sql）

insert into car(id, name, color) values (1, 'Toyota Camry', 'blue');
insert into car(id, name, color) values (2, 'Suzuki Swift', 'yellow');
insert into car(id, name, color) values (3, 'Nissan Qashqai', 'red');

操作是
(1) 创建的初始记录
(2) 删除所有记录
(3) 添加新记录
(4) 删除所有记录

进行断言时，发现结果列表仍然包含最后一条记录，因此断言失败。

我想知道这是否是由于在插入之前没有完成删除操作造成的。

感谢您对此提供一些见解，非常感谢。

模型（Car.java）：

package com.example.demo.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import io.swagger.v3.oas.annotations.media.Schema;
import lombok.Data;

@ApiModel(value = "Car", description = "The model for car")
@Schema
@Entity
@Data
public class Car {
    @ApiModelProperty(notes = "Car ID.", example = "12345", required = false, position = 0)
    @Id
    @GeneratedValue
    private Long id;

    @ApiModelProperty(notes = "Car name.", example = "Suzuki Swift 2020", required = true, position = 1)
    @NotNull
    @Size(min = 1, max = 30, message = "Name must have length between 1 and 30")
    private String name;

    @ApiModelProperty(notes = "Car color.", example = "blue", required = true, position = 2)
    @NotNull
    @Size(min = 1, max = 30, message = "Color must have length between 1 and 30")
    private String color;
}

存储库 (CarReposiroty.java)

package com.example.demo.repo;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

import com.example.demo.model.Car;

@Repository
public interface CarRepository extends JpaRepository<Car, Long> {

}

服务（TestService.java）

package com.example.demo.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.example.demo.model.Car;
import com.example.demo.repo.CarRepository;

@Service
public class TestService {

    @Autowired
    private CarRepository carRepository;

    public List<Car> getAllCars() {
        return carRepository.findAll();
    }

    @Transactional
    public void addNewCar(Car car) {
        carRepository.save(car);
    }

    @Transactional
    public void deleteAllCars() {
        carRepository.deleteAll();
    }
}

JUnit

...
......
@Test
public void shouldBeAbleToDeleteCarAndAddCarAndGetAllCars() {
    testService.deleteAllCars();

    Car car = new Car();
    car.setName("123456789012345678901234567890");
    car.setColor("123456789012345678901234567890");

    testService.addNewCar(car);

    List<Car> carList = testService.getAllCars();

    assertEquals(1, carList.size());

    testService.deleteAllCars();
}
...
......

Spring Boot v2.3.1

pom.xml

    ...
    .....
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-validation</artifactId>
    </dependency>
    ...
    ......

Spring 休眠配置 (application-test.yml)

spring.datasource.url: jdbc:mysql://[the host url]:3306/test
spring.datasource.username: [the username]
spring.datasource.password: [the password]
spring.jpa.hibernate.ddl-auto: create-drop
spring.datasource.initialization-mode: always

MySQL 8.0.17

Answer 1

这是因为deleteAllCars() 没有将更改提交到数据库，并且测试方法中的所有操作都包装在单个事务中，因为正在传播事务。在测试类上添加以下注释

@Transactional(propagation = Propagation.NEVER)

也检查这个相关问题How to flush data into db inside active spring transaction?