Question

Hibernate不想为子实体保存ID。我有以下表格：

@Entity
@Table(name = "ct_orders")
data class Order(

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = javax.persistence.GenerationType.IDENTITY)
    val id: Int = 0,

    @OneToMany(fetch = FetchType.LAZY, cascade = arrayOf(CascadeType.ALL), mappedBy = "order")
    val route: List<Route>? = null,

    ...

)

@Entity
@Table(name = "ct_routes")
@JsonIgnoreProperties("id", "order")
data class Route(

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    val id: Int = 0,

    @Column
    val location: Point = GeoHelpers.point(),

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "order_id")
    val order: Order? = null,

    @Column
    val title: String = ""

)

ct_routes在order_id中使用null保存。关系有问题吗？或者，我的代码可能有问题吗？

以下是代码的一部分，它保存了一个Order实体：

val order = orderRepository.save(Order(
    ...
    route = GeoHelpers.placesListToEntities(data.places),
    ...
))

fun placesListToEntities(points: List<PlaceDto>) = points.map {
    Route(
        location = Helpers.geometry(it.location.latitude, it.location.longitude),
        title = it.title
    )
}

Answer 1

您正在对bidirectional @OneToMany进行建模，并且如文档中的示例所示，您负责在子项上设置父值>实体：

val order = orderRepository.save(Order(...).apply{
    ...
    route = GeoHelpers.placesListToEntities(this, data.places),
    ...
})

fun placesListToEntities(order:Order, points: List<PlaceDto>) = points.map {
    Route(
        order = order,
        location = Helpers.geometry(it.location.latitude, it.location.longitude),
        title = it.title
    )
}

PS。由于Route是一个entity，您可以稍微更改一下模型以强制执行langauge级别的约束，即：

class Route internal constructor() {
    lateinit var order: Order

    constructor(order: Order) : this() {
        this.order = order
    }
}

有关详细信息，请参阅this question。

Hibernate使用null父ID保存子实体

1 个答案: