问题描述
我目前在 Spring Boot 中使用 GraphQL SPQR。为了提高数据库性能,我使用 @GraphQLEnvironment ResolutionEnvironment
编写了自定义逻辑,我已经能够找到所有请求的值并将它们过滤为 @Entity
注释,然后我使用这些来创建一个用于 Eager 获取这些特定值的动态 EntityGraph。
现在,这似乎适用于映射为 @OnetoMany
的实体,但是我的 @ManyToOne
和 @OnetoOne
实体即使未选择它们仍然会进行单独的 Hibernate sql 查询(当它们被选择时,它们Eager 是作为 Join 获取的)。
我尝试了很多不同的东西,例如 Hibernate Enhanced Bytecode 和使用 LazyInitilization 确实会阻止这些实体被加载 - 但是当它们被选中时,它似乎也会进行连接和单独的选择查询。
Hibernate:
/* select
generatedalias0
from
OwningJob as generatedalias0
where
generatedalias0.jobNumber=:param0 */ select
owningjob0_.pkId as pkid1_13_0_,customer1_.customerPkId as customer1_0_1_,owningjob0_.customerCode as customer7_13_0_,...
from
dbo.OwningJob owningjob0_
left outer join
dbo.Customer customer1_
on owningjob0_.CustomerCode=customer1_.customerId
where
owningjob0_.OwningJobId=?
Hibernate:
/* sequential select
uk.co.essl.jobloadapi.model.jobapi.OwningJob */ select
owningjob_.CustomerCode as customer7_13_
from
dbo.OwningJob owningjob_
where
owningjob_.pkId=?
我不明白为什么会发出额外的选择请求,似乎 Hibernate 很困惑,因为它已经被 Eagerly 加载了?
这也导致了 N+1 问题,任何关于出了什么问题的想法。我也愿意接受完全不同的方法!
实体类的一部分:
@Entity
@Table(name = "OwningJob",schema = "dbo")
@GraphQLType(name = "Order",description = "Order description.")
@Getter
public class OwningJob {
@ManyToOne
@JoinColumn(name = "CustomerCode",referencedColumnName = "CustomerId")
@LazyToOne(LazyToOneOption.NO_PROXY)
@LazyGroup("owningJob_customer")
public Customer customer;
}
编辑:
我现在已经尝试使用 JPA Criteria API,但我似乎仍然得到相同的行为:
CriteriaBuilder builder = entityManager.getCriteriaBuilder();
CriteriaQuery<Object> criteria = builder.createquery(Object.class);
Root<OwningJob> root = criteria.from(OwningJob.class);
Path<String> customerReference = root.get("customerReference");
Path<String> jobNumber_ = root.get("jobNumber");
Path<Object> customerPath = root.join("customer");
criteria = criteria
.multiselect(customerReference,jobNumber_,customerPath)
.where(builder.equal(root.get("jobNumber"),jobNumber));
这会导致这两个查询都触发...
Hibernate:
select
owningjob0_.customerReference as col_0_0_,owningjob0_.OwningJobId as col_1_0_,customer1_.customerPkId as col_2_0_,customer1_.customerPkId as customer1_0_,customer1_.customerId as customer2_0_,customer1_.customerName as customer3_0_
from
dbo.OwningJob owningjob0_
inner join
dbo.Customer customer1_
on owningjob0_.CustomerCode=customer1_.customerId
where
owningjob0_.OwningJobId=?
Hibernate:
select
customer0_.customerPkId as customer1_0_0_,customer0_.customerId as customer2_0_0_,customer0_.customerName as customer3_0_0_
from
dbo.Customer customer0_
where
customer0_.customerId=?
解决方法
暂无找到可以解决该程序问题的有效方法,小编努力寻找整理中!
如果你已经找到好的解决方法,欢迎将解决方案带上本链接一起发送给小编。
小编邮箱:dio#foxmail.com (将#修改为@)