JPA标准在多一关系中查询

Question

我在Eclipselink 2.3.2中使用JPA 2.0，其中我之间的产品及其颜色之间有着多一的关系。产品可以具有多种颜色，并且颜色可以与许多产品相关联。这种关系在数据库中通过三个表表示。

• 产品
• prod_colour（加入表）
• 颜色

这 prod_colour 表有两个参考列 prod_id 和 colour_id 从相关的父表中 product 和 colour 分别。

很明显，实体班 Product 有一组颜色 - java.util.Set<Colour> 命名 colourSet.

实体类 Colour 有一组产品 - java.util.Set<Product> 命名 productSet.

我需要从 colour 桌子 基于 prodId 提供 做到了 不是 匹配颜色 prod_colour 桌子。

---

相应的JPQL将是以下内容。

FROM Colour colour 
WHERE colour.colourId 
NOT IN(
SELECT colours.colourId 
     FROM Product product 
     INNER JOIN product.colourSet colours 
     WHERE product.prodId=:id) 
ORDER BY colour.colourId DESC

它生成以下SQL语句。

SELECT t0.colour_id, t0.colour_hex, t0.colour_name 
FROM projectdb.colour t0 
WHERE t0.colour_id 
NOT IN (
       SELECT DISTINCT t1.colour_id 
       FROM prod_colour t3, projectdb.product t2, projectdb.colour t1 
       WHERE ((t2.prod_id = ?)
       AND ((t3.prod_id = t2.prod_id) 
       AND (t1.colour_id = t3.colour_id)))) 
ORDER BY t0.colour_id DESC

由于这反过来是运行时间查询，因此最好使用标准查询。我没有洞察力可以在这种复杂的关系中构建标准查询。

到目前为止，我的查询与前面的JPQL完全无关。

CriteriaBuilder criteriaBuilder=entityManager.getCriteriaBuilder();
CriteriaQuery<Colour>criteriaQuery=criteriaBuilder.createQuery(Colour.class);
Metamodel metamodel = entityManager.getMetamodel();
EntityType<Colour> entityType = metamodel.entity(Colour.class);
Root<Colour> root = criteriaQuery.from(entityType);
SetJoin<Colour, Product> join = root.join(Colour_.productSet, JoinType.INNER);
ParameterExpression<Long> parameterExpression=criteriaBuilder.parameter(Long.class);
criteriaQuery.where(criteriaBuilder.equal(join.get(Product_.prodId), parameterExpression));  

TypedQuery<Colour> typedQuery = entityManager.createQuery(criteriaQuery).setParameter(parameterExpression, prodId);
List<Colour> list=typedQuery.getResultList();

如何编写与给出的JPQL相对应的标准查询？

---

编辑：

此标准查询：

CriteriaBuilder criteriaBuilder=entityManager.getCriteriaBuilder();
CriteriaQuery<Tuple>criteriaQuery=criteriaBuilder.createQuery(Tuple.class);
Metamodel metamodel = entityManager.getMetamodel();
EntityType<Colour> entityType = metamodel.entity(Colour.class);
Root<Colour> root = criteriaQuery.from(entityType);
criteriaQuery.multiselect(root.get(Colour_.colourId));
SetJoin<Colour, Product> join = root.join(Colour_.productSet, JoinType.INNER);
ParameterExpression<Long> parameterExpression=criteriaBuilder.parameter(Long.class);
criteriaQuery.where(criteriaBuilder.equal(join.get(Product_.prodId), parameterExpression));

TypedQuery<Tuple> typedQuery = entityManager.createQuery(criteriaQuery).setParameter(parameterExpression, prodId);
List<Tuple> list = typedQuery.getResultList();

反过来产生以下SQL查询。

SELECT t0.colour_id 
FROM projectdb.colour t0, prod_colour t2, projectdb.product t1 
WHERE ((t1.prod_id = 1) 
AND ((t2.colour_id = t0.colour_id) 
AND (t1.prod_id = t2.prod_id))))

如何将此查询与子查询相关联，以便产生以下SQL查询？

SELECT t0.colour_id, t0.colour_hex, t0.colour_name 
FROM projectdb.colour t0 
WHERE t0.colour_id 
NOT IN (
       SELECT t0.colour_id 
       FROM projectdb.colour t0, prod_colour t2, projectdb.product t1 
       WHERE ((t1.prod_id = 1) 
       AND ((t2.colour_id = t0.colour_id) 
       AND (t1.prod_id = t2.prod_id))))
ORDER BY t0.colour_id DESC   

---

编辑：

以下标准查询 NOT EXISTS() 作品。

CriteriaBuilder criteriaBuilder=entityManager.getCriteriaBuilder();
CriteriaQuery<Colour>criteriaQuery=criteriaBuilder.createQuery(Colour.class);
Metamodel metamodel = entityManager.getMetamodel();
EntityType<Colour> entityType = metamodel.entity(Colour.class);
Root<Colour> root = criteriaQuery.from(entityType);
criteriaQuery.select(root);
Subquery<Long>subquery=criteriaQuery.subquery(Long.class);
Root<Product> subRoot = subquery.from(Product.class);
subquery.select(root.get(Colour_.colourId));
Predicate paramPredicate = criteriaBuilder.equal(subRoot.get(Product_.prodId), prodId);
Predicate correlatePredicate = criteriaBuilder.equal(root.get(Colour_.productSet), subRoot);
subquery.where(criteriaBuilder.and(paramPredicate, correlatePredicate));
criteriaQuery.where(criteriaBuilder.exists(subquery).not());
criteriaQuery.orderBy(criteriaBuilder.desc(root.get(Colour_.colourId)));

TypedQuery<Colour> typedQuery = entityManager.createQuery(criteriaQuery);
List<Colour>list= typedQuery.getResultList();

但是，它以不必要的/额外的/冗余（如以下方式）生成SQL查询（尽管似乎是返回所需的结果集，但似乎是如此）。

SELECT t0.colour_id, t0.colour_hex, t0.colour_name 
FROM projectdb.colour t0 
WHERE 
NOT (EXISTS (
       SELECT t0.colour_id 
       FROM prod_colour t3, projectdb.product t2, projectdb.product t1 
       WHERE (((t1.prod_id = 1) 
       AND (t1.prod_id = t2.prod_id)) 
       AND ((t3.colour_id = t0.colour_id) 
       AND (t2.prod_id = t3.prod_id)))))
ORDER BY t0.colour_id DESC

这应该只是

SELECT t0.colour_id, t0.colour_hex, t0.colour_name 
FROM projectdb.colour t0 
WHERE 
NOT (EXISTS (
       SELECT t0.colour_id 
       FROM prod_colour t3, projectdb.product t2
       WHERE (((t2.prod_id = 1)) 
       AND ((t3.colour_id = t0.colour_id) 
       AND (t2.prod_id = t3.prod_id)))))
ORDER BY t0.colour_id DESC

有没有办法与 NOT IN() 子句而不是 NOT EXISTS() 并摆脱这种多余的加入？

该查询产生的冗余联接已经报告为 漏洞.

Answer 1

以下是有关的标准查询 NOT IN() （但是，我更喜欢 NOT EXISTS() 超过 NOT IN()).

CriteriaBuilder criteriaBuilder=entityManager.getCriteriaBuilder();
CriteriaQuery<Colour>criteriaQuery=criteriaBuilder.createQuery(Colour.class);
Metamodel metamodel = entityManager.getMetamodel();
EntityType<Colour> entityType = metamodel.entity(Colour.class);
Root<Colour> root = criteriaQuery.from(entityType);
criteriaQuery.select(root);

Subquery<Long>subquery=criteriaQuery.subquery(Long.class);
Root<Product> subRoot = subquery.from(Product.class);
subquery.select(root.get(Colour_.colourId));

Predicate paramPredicate = criteriaBuilder.equal(subRoot.get(Product_.prodId), prodId);
Predicate correlatePredicate = criteriaBuilder.equal(root.get(Colour_.productSet), subRoot);

subquery.where(criteriaBuilder.and(paramPredicate, correlatePredicate));
criteriaQuery.where(criteriaBuilder.in(root.get(Colour_.colourId)).value(subquery).not());
criteriaQuery.orderBy(criteriaBuilder.desc(root.get(Colour_.colourId)));

TypedQuery<Colour> typedQuery = entityManager.createQuery(criteriaQuery);
List<Colour> list=typedQuery.getResultList();

这会产生以下SQL查询。

SELECT t0.colour_id, t0.colour_hex, t0.colour_name 
FROM projectdb.colour t0 
WHERE NOT 
(t0.colour_id IN (
                 SELECT t0.colour_id 
                 FROM prod_colour t3, projectdb.product t2, projectdb.product t1 
                 WHERE (((t1.prod_id = ?) 
                 AND (t1.prod_id = t2.prod_id)) 
                 AND ((t3.colour_id = t0.colour_id) 
                 AND (t2.prod_id = t3.prod_id))))) 
ORDER BY t0.colour_id DESC

此查询返回所需的结果集。但是，它会产生多余的联接，但这似乎是 漏洞.

---

编辑：

试 相同的查询 在Hibernate上，编写此标准查询的方式看起来不正确。联合和子查询的组合导致产生正确的SQL查询。

CriteriaBuilder criteriaBuilder=entityManager.getCriteriaBuilder();
CriteriaQuery<Colour>criteriaQuery=criteriaBuilder.createQuery(Colour.class);
Metamodel metamodel = entityManager.getMetamodel();
EntityType<Colour> entityType = metamodel.entity(Colour.class);
Root<Colour> root = criteriaQuery.from(entityType);
criteriaQuery.select(root);

Subquery<Long>subquery=criteriaQuery.subquery(Long.class);
Root<Colour> subRoot = subquery.from(Colour.class);
subquery.select(subRoot.get(Colour_.colourId));
SetJoin<Colour, Product> join = subRoot.join(Colour_.productSet, JoinType.INNER);

ParameterExpression<Long> parameterExpression=criteriaBuilder.parameter(Long.class);
criteriaQuery.where(criteriaBuilder.in(root.get(Colour_.colourId)).value(subquery).not());
subquery.where(criteriaBuilder.equal(join.get(Product_.prodId), parameterExpression));
criteriaQuery.orderBy(criteriaBuilder.desc(root.get(Colour_.colourId)));

TypedQuery<Colour> typedQuery = entityManager.createQuery(criteriaQuery);
List<Colour> list = typedQuery.setParameter(parameterExpression, 1L).getResultList();

这将产生以下SQL查询，然后将其委派给MySQL。

SELECT t0.colour_id, t0.colour_name, t0.colour_hex
FROM projectdb.colour t0
WHERE NOT (t0.colour_id IN 
          (SELECT t1.colour_id
           FROM prod_colour t3, projectdb.product t2, projectdb.colour t1
           WHERE ((t2.prod_id = ?)
           AND ((t3.colour_id = t1.colour_id)
           AND (t2.prod_id = t3.prod_id)))))
ORDER BY t0.colour_id DESC