SpringDataJPA详解增删改查操作方法

public interface ResumeDao extends JpaRepository<Resume, Long>, JpaSpecificationExecutor<Resume> {
    @Query("from Resume where id=?1") // 这个"1"代表的下面方法形参中引入参数的位置作为查询id
    public Resume findByJpql(Long id); // 使用jpql语句根据id查询数据
}

   @Test
    public void testJpql() {
        Resume byJpql = resumeDao.findByJpql(1L);
        System.out.println(byJpql);
    }

public interface ResumeDao extends JpaRepository<Resume, Long>, JpaSpecificationExecutor<Resume> { 
    
    @Query(value = "select * from tb_resume where id=?1", nativeQuery = true)
    public Resume findBySql(Long id); // 使用sql语句根据id查询数据
}

@Test
    public void testSql() {
        Resume byJpql = resumeDao.findByJpql(2L);
        System.out.println(byJpql);
    }

public interface ResumeDao extends JpaRepository<Resume, Long>, JpaSpecificationExecutor<Resume> {
 
    public List<Resume> findByNameLike(String name);
    public List<Resume> findByNameLikeAndAddress(String name, String address);
}

    @Test
    public void testMethodName() {
        List<Resume> list = resumeDao.findByNameLike("张%");
        System.out.println(list);
    }
    @Test
    public void testMethodName2() {
        List<Resume> list = resumeDao.findByNameLikeAndAddress("张%", "北京");
        System.out.println(list);
    }

 @Test
    public void testSpecification() {
        
        Specification<Resume> specification = new Specification<Resume>() {
            @Override
            public Predicate toPredicate(Root<Resume> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder criteriaBuilder) {
                // 获取到name属性
                Path<Object> name = root.get("name");
                // 使用CriteriaBuilder针对name属性构建条件（精准查询）
                Predicate predicate = criteriaBuilder.equal(name, "张三");
                return predicate;
            }
        };
        Optional<Resume> optional = resumeDao.findOne(specification);
        Resume resume = optional.get();
        System.out.println(resume);
    }

@Test
    public void testSpecificationMultiCon() {
        
        Specification<Resume> specification = new Specification<Resume>() {
            @Override
            public Predicate toPredicate(Root<Resume> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder criteriaBuilder) {
                // 获取到name属性
                Path<Object> name = root.get("name");
                Path<Object> address = root.get("address");
                // 条件1：使用CriteriaBuilder针对name属性构建条件（精准查询）
                Predicate predicate1 = criteriaBuilder.equal(name, "张三");
                // 条件2：address以"北"开头（模糊匹配）
                Predicate predicate2 = criteriaBuilder.like(address.as(String.class), "北%"); // as作用将其转换为Expression，并且指定参数类型
                // 组合两个条件
                Predicate predicate = criteriaBuilder.and(predicate1, predicate2);
                return predicate;
            }
        };
        Optional<Resume> optional = resumeDao.findOne(specification);
        Resume resume = optional.get();
        System.out.println(resume);
    }

@Test
    public void testSort() {
        Sort sort = new Sort(Sort.Direction.DESC, "id"); // 根据id进行倒序
        List<Resume> list = resumeDao.findAll(sort);
        for (int i = 0; i < list.size(); i++) {
            Resume resume = list.get(i);
            System.out.println(resume);
        }
    }

@Test
    public void testPage() {
        
        Pageable pageable = PageRequest.of(0, 2);
        Page<Resume> all = resumeDao.findAll(pageable);
        System.out.println(all);
    }