Java QueryDsl - 集合表达式中的子查询
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QueryDsl - subquery in collection expression
提问by wiecia
I'm using spring-data-jpa and querydsl (3.2.3)
I have a scenario where I'm creating set of predicates based on user filer/input. All of these comes to BooleanExpression.
我正在使用 spring-data-jpa 和 querydsl (3.2.3)
我有一个场景，我正在根据用户文件管理器/输入创建一组谓词。所有这些都归结于BooleanExpression。
My simplified model looks as following:
我的简化模型如下所示：
@Entity
public class Invoice {
@ManyToOne
private Supplier supplier;
}
@Entity
public class Supplier {
private String number;
}
@Entity
public class Company {
private String number;
private boolean active
}
Now, what I'm struggling with is this query:
现在，我正在苦苦挣扎的是这个查询：
SELECT * FROM Invoice WHERE invoice.supplier.number in (SELECT number from Company where active=true)
So basically I need to subquery in CollectionExpressionlike format that will fetch all companies numbers and sets this into in() expression.
所以基本上我需要以CollectionExpression类似的格式进行子查询，该格式将获取所有公司编号并将其设置为 in() 表达式。
My spring-data repositories implements CustomQueryDslJpaRepositorywhich in turn extends JpaRepositoryand QueryDslPredicateExecutor.
I hope the answer to this is straightforward, but I'm quite new to querydsl and didn't find the solutions so far.
我的 spring-data 存储库实现了CustomQueryDslJpaRepository它依次扩展JpaRepository和QueryDslPredicateExecutor.
我希望这个问题的答案很简单，但我对 querydsl 很陌生，到目前为止还没有找到解决方案。
采纳答案by Timo Westk?mper
Here is a variant of jaiwo99's answer in a more JPAesque form
这是 jaiwo99 的答案的变体，采用更 JPAesque 的形式
BooleanExpression exp = invoice.supplier.number.in(new JPASubQuery()
.from(company)
.where(company.active.isTrue())
.list(company.nu??mber));
Feel free to merge this into the original answer.
随意将其合并到原始答案中。
回答by Jaiwo99
Try this:
尝试这个：
QInvoice invoice = QInvoice.invoice;
QCompany company = QCompany.company;
List<Invoice> list = new HibernateQuery(sessionFactory.getCurrentSession())
.from(invoice).where(
new HibernateSubQuery().from(invoice, company).where(
invoice.supplier.number.eq(company.number).and(
company.active.eq(true))).exists()).list(invoice);
