JPA CriteriaDelete与in子查询：确保数据操作正确执行

// 假设 orphan, one_type, other_type, key, givenList 已定义
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaDelete<Y> criteriaDelete = criteriaBuilder.createCriteriaDelete(orphan);

Root<Y> deleteRoot = criteriaDelete.from(one_type); // 主查询的根实体

// 构建子查询，用于in表达式
CriteriaQuery<T> criteriaQuery = criteriaBuilder.createQuery(other_type); // 子查询的返回类型
Root<T> queryRoot = criteriaQuery.from(other_type); // 子查询的根实体
criteriaQuery.select(queryRoot.get(key)); // 子查询选择的字段
criteriaQuery.where(queryRoot.get("id").in(givenList)); // 子查询的过滤条件

// 将子查询的结果列表用于主删除查询的in表达式
entityManager.createQuery(criteriaDelete
        .where(deleteRoot.in(entityManager.createQuery(criteriaQuery).getResultList())));

import javax.persistence.EntityManager;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaDelete;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import java.util.List;

// 假设 Y 和 T 是 JPA 实体
// class Y { private Object matchingFieldInY; ... }
// class T { private Object id; private Object key; ... }

public class JpaCriteriaDeleteExecutor {

    private EntityManager entityManager; // 假设 entityManager 已注入或获取

    public JpaCriteriaDeleteExecutor(EntityManager entityManager) {
        this.entityManager = entityManager;
    }

    public int deleteEntitiesWithSubquery(List<Object> givenList) {
        CriteriaBuilder cb = entityManager.getCriteriaBuilder();

        // 1. 构建子查询：获取T实体中'key'字段的值列表
        CriteriaQuery<Object> subCriteriaQuery = cb.createQuery(Object.class); // 子查询选择单个字段，返回类型为Object
        Root<T> subQueryRoot = subCriteriaQuery.from(T.class);
        subCriteriaQuery.select(subQueryRoot.get("key")); // 选择T实体中的'key'字段
        subCriteriaQuery.where(subQueryRoot.get("id").in(givenList)); // 根据'id'列表过滤T实体

        // 2. 执行子查询，获取in表达式所需的值列表
        List<Object> keysToMatch = entityManager.createQuery(subCriteriaQuery).getResultList();

        // 3. 构建主 CriteriaDelete 查询
        CriteriaDelete<Y> deleteQuery = cb.createCriteriaDelete(Y.class);
        Root<Y> deleteRoot = deleteQuery.from(Y.class);

        // 4. 应用in谓词：删除Y实体中'matchingFieldInY'字段值在keysToMatch列表中的记录
        // 注意：这里假设Y实体有一个字段'matchingFieldInY'与T实体的'key'字段类型兼容
        deleteQuery.where(deleteRoot.get("matchingFieldInY").in(keysToMatch));

        // 5. 关键步骤：创建Query对象并调用executeUpdate()
        int deletedCount = entityManager.createQuery(deleteQuery).executeUpdate();

        System.out.println("成功删除了 " + deletedCount + " 条记录。");
        return deletedCount;
    }
}