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[英]hibernate - How to do a Projection based on a subquery using Criteria API?
[英]How to create a subquery using criteria Api
我嘗試按照標准 Api 執行以下 JPQL 條款
SELECT new ProductDTOOut(p.id,p.name,
(SELECT pr.price FROM Price pr WHERE pr.product.id = p.id and pr.company.id = :companyId) )
FROM Product p
沒有成功,我該怎么辦?
tnx 高級
我知道解決我的問題按照答案:
CriteriaBuilder cb = manager.getCriteriaBuilder();
CriteriaQuery<ProductDTOOut> criteriaQuery = cb.createQuery(ProductDTOOut.class);
// create query
Root<Product> rootFrom = criteriaQuery.from(Product.class);
// creating subquery
Subquery<Double> subquery = criteriaQuery.subquery(Double.class);
Root<Price> subqueryRoot = subquery.from(Price.class);
subquery.select(subqueryRoot.get(Price_.PRICE));
subquery.where(
cb.equal(rootFrom.get(Product_.ID),
subqueryRoot.get(Price_.PRODUCT).get(Product_.ID)),
cb.equal(
subqueryRoot.get(Price_.COMPANY).get(Company_.ID), companyId));
criteriaQuery.select(cb.construct(ProductDTOOut.class,
rootFrom.get(Product_.ID),
rootFrom.get(Product_.NAME),
subquery // here put subquery
));
TypedQuery<ProductDTOOut> query = manager.createQuery(criteriaQuery);
return query.getResultList();
我希望我能幫助有同樣問題的人。
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