jpa条件查询与分页条件查询

首先JpaSpecificationExecutor这个接口的重载的findAll方法，Specification 用于拼接条件Pageable分页参数，Sort排序参数。简单记录分页查询实现方式

查询结果

Hibernate: select user0_.id as id1_0_, user0_.age as age2_0_, user0_.creat_date as creat_da3_0_, user0_.name as name4_0_, user0_.pwd as pwd5_0_, user0_.title as title6_0_, user0_.update_date as update_d7_0_ from user user0_ where user0_.name=? and (user0_.age>10 or user0_.id<5) order by user0_.age asc, user0_.creat_date desc limit ?
2021-09-28 15:33:52.180 TRACE 7064 --- [nio-8080-exec-4] o.h.type.descriptor.sql.BasicBinder      : binding parameter [1] as [VARCHAR] - [laowang]

代码：

@Override
    public Page<User> listPageAllUser(PageData<User> pageData) {
        //2、jpa 自带的分页查询，可组装条件的
        Pageable pageable = PageRequest.of(pageData.getPageNumber()-1, pageData.getPageSize(),
                Sort.by("age").ascending().and(Sort.by("creatDate").descending()));
        /*
         * @param root:代表的查询的实体类
         * @param query：可以从中得到Root对象，即告知JPA Criteria查询要查询哪一个实体类，
         * 还可以来添加查询条件，还可以结合EntityManager对象得到最终查询的TypedQuery 对象
         * @Param cb:criteriabuildre对象，用于创建Criteria相关的对象工程，当然可以从中获取到predicate类型
         * @return:代表一个查询条件
         */
        Specification<User> specification = (Specification<User>) (root, query, criteriaBuilder) -> {
            Path age = root.get("age");
            Path id = root.get("id");
            Predicate p1 = criteriaBuilder.gt(age,pageData.getParams().getAge());
            Predicate p2 = criteriaBuilder.lt(id,pageData.getParams().getId());
            Predicate p3 = criteriaBuilder.equal(root.get("name").as(String.class), pageData.getParams().getName());
            Predicate p = criteriaBuilder.and(p3,criteriaBuilder.or(p1,p2));
            return p;
        };
        Page<User> page = userDao.findAll(specification,pageable);
        return page;
    }

参考文章：jpa specification条件查询

下面同事总结的图

标签：user0,jpa,age,criteriaBuilder,查询,_.,条件,pageData
来源： https://www.cnblogs.com/wangzph/p/15349631.html