我的应用程序中有一个性能问题。休眠使查询太多
我有三个实体与下面的关系:
one Order => many OrderLines => Many Cards
实体从数据库负载需要太多的时间,在orderLines都装有预先加载,而卡都含有延迟加载。为了让应用程序流畅,需要延迟加载。
我需要配置一个案件的急切加载,我需要帮助来做到这一点。
我使用jhsipster堆栈:春季启动与JPA
我试着写HQL查询
@Query(value = "from Order as order "
+ "inner join order.orderLines as orderLines "
+ "inner join orderlines.cards gc "
+ "where order.id= :order")
Order findWithDependencies(@Param("order")Long order);
我不得不取消错误:意外的标记顺序(2号线)
我尝试与本机查询
@Query(value = "select * "+
"from order_table ot "+
"left join order_line ol ON ot.id = ol.order_id "+
"left join giftcard gc ON gc.orderline_id = ol.id "+
"where ot.id=:order", nativeQuery= true)
Order findWithDependenciesNative(@Param("order")Long order);
但是,当我做
orderLine.getCard()
从代码,Hibernate仍然做查询从数据库中获取数据,并导致我的表现问题。实体
必要的代码:
public class Order implements Serializable {
@OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
@JoinColumn(name = "order_id", nullable = false)
@Size(min = 1)
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
@JsonProperty("detail")
@Valid
private List<OrderLine> orderLines = new ArrayList<>();
}
public class OrderLine extends AbstractAuditingEntity implements Serializable, Comparable {
@OneToMany
@JoinColumn(name = "orderline_id")
@JsonIgnore
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
private Set<Giftcard> giftcards = new HashSet<>();
}
public class Giftcard extends AbstractAuditingEntity implements Serializable, Comparable {
@ManyToOne(optional = true)
@JoinColumn(name= "orderline_id")
@JsonIgnore
private OrderLine orderLine;
}
我的代码实际上
{
Order order = orderRepository.findWithDependenciesNative(linkFile.getOrder());
//Some code
List<OrderLine> orderLines = order.getOrderLines();
orderLines.sort(Comparator.comparing(OrderLine::getId));
for (OrderLine orderLine : orderLines) {
Stream<Card> cards = orderLine.getCards().stream().sorted(Comparator.comparing(Card::getCardNumber));
for (Card card : cards.collect(Collectors.toList())) {
//Some code
}
}
的问题是在第二的foreach,为每卡休眠执行两个查询,并与参加该请求不加载数据像渴望的配置。你有想法帮助我吗?
非常感谢
在第一个查询使用别的东西作为'order'和':order'因为这是很明显一个SQL关键字,这就是为什么休眠为您提供了错误有。 –