由于生成的SQL使用别名-您可能需要进行单独的查询以获取总行数。例如:
原因在于数据库中存储的数据是跨表的,而且还要做count统计,这样得到的结果就不是原生的MySQL表,我用的又是JPA技术。我们知道,使用JPA第一步就是映射实体,每一张表就至少对应一个实体(力求严谨,因为联合主键时一张表会对应两个对象)。可是对于灵活的查询尤其是连接查询,并不存在一个真正的表与其对应,怎么样才能解...
policy); // Wrap the native query in a standard JPA Query and execute it Query query = JpaHelper.createQuery(q, em); return query.getSingleResult();
I want to find records for related_elements table, where relationId belongs to a list suppose a Set tempSet contains[2,3,4] I have to check for these value contains in related_element table using jpa criteria query CriteriaBuilder cb1=entityManager.getCriteriaBuilder(); CriteriaQuery<RelatedEleme...
totalCount/pageSize:totalCount/pageSize+1;pagination.setTotalPage(totalPage);//数据处理(根据你的业务对查询结果进行处理)//TODOpagination.setRecords(resultList);returnpagination;}privateList<CarDetailDto>listQuery(Condition condition,Integer currentPage,Integer pageSize){CriteriaBuilder cb=entityManager.get...
The following sequence diagram shows the sequence of method calls involved in counting records using JPA: MainQueryEntityManagerUserRepoMainQueryEntityManagerUserRepocreateQuery("SELECT COUNT(u) FROM User u")executeQuery()getSingleResult()userCountprint userCount ...
JPA NamedQuery与聚合函数和group by一起使用 JPA(Java Persistence API)是Java持久化规范的一部分,它提供了一种方便的方式来访问和管理数据库中的数据。JPA NamedQuery是一种在实体类中定义的查询语句,可以通过名称来引用和执行。 聚合函数是一种用于对数据进行统计和计算的函数,例如求和、平均值、最大值...
In Hibernate you can unwrap a jakarta.persistence.Query to org.hibernate.Query and then call setTupleTransformer(NativeQueryConstructorTransformer), it converts query result to an object using constructor arguments (which is suitable for Records). But as I have no experience with EclipseLink, don'...
}privateObjectuseMybatisPage(Object result,PageRequest pageRequest,intcount){Pagepage=newPage(); page.setCurrent( pageRequest.getPageNumber() ); page.setSize( pageRequest.getPageSize() ); page.setTotal( count ); page.setRecords( (List) result );//只能返回List 所以外部list.get(0);List<Page...
publicListgetCurrentResults(){ returnem.createQuery("select a from Activity a").setMaxResults(10).getResultList(); } The above example returns the first 10 records based on the Query order. On the other hand, if you want to return a limited pagesize starting from an offset, then ...