Spring Boot Unit测试唯一约束被忽略

Question

我的应用程序REST控制器在单元测试和正常运行之间遇到了不同的行为。我在我的一个字段上添加了一个@Column（unique = true）来约束一个唯一的数字，不知怎的，它在单元测试中被忽略了，我无法理解为什么。我在下面展示了一个简短的例子，基本上将两辆车的数量相同的车辆添加到商店：

@Test
    public void CreateVehicle_SameNR_NOK() {
        Shop shop = shopController.createVehicle(0L,1,new Vehicle("AAA",
                "111222"));
        Assert.assertEquals(shop.getVehicles().size(),1);

        shopController.createVehicle(0L,1,new Vehicle("AAA",
                "111222"));

        Assert.assertEquals(shop.getVehicles().size(),1); //This fails.
    }


@Entity
public class Vehicle {

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE)
    private long id;

    @NotNull
    private String name;

    @NotNull
    @Column(unique = true) //ignored in unit test?
    private String nr;


    protected Vehicle() {}

    public Vehicle(String name, String nr) {
        this.name = name;       
        this.nr = nr;        
    }   

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }   

    public String getNr() {
        return nr;
    }

    public void setNr(String nr) {
        this.nr = nr;
    }  
}

application.properties

spring.datasource.url=jdbc:h2:mem:test_mem;DB_CLOSE_ON_EXIT=FALSE
spring.datasource.username=sa
spring.datasource.password=
spring.datasource.driver-class-name=org.h2.Driver
logging.level.org.springframework.web=DEBUG
debug=true

ShopController提取

@RequestMapping(value ="{id}/shop/{shopId}/vehicle", method = RequestMethod.POST)
    public Shop createShopVehicle(@PathVariable Long id, @PathVariable Long shopId, @RequestBody Vehicle vehicle) {
        Shop shop = shopRepository.findOne(shopId);
        shop.getVehicles().add(vehicle);
        shopRepository.save(shop);
        return shop;
    }