JPA 完全动态和多级标准 api

Question

我正在尝试了解如何创建一个 JPA Critera 查询，该查询允许具有多个级别的完全动态过滤。

例如

select * 
from table 
where (
       (column1 = 'A'
        and 
       (column2 = 'B' or column3 = 'C')
      )
      or
      column3 = 'D'  

Answer 1

您需要按照下面的测试创建规范。这可以是动态的。

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes=HelloWorldConfig.class)
public class SpecificationTest {

    @Autowired
    private AccountRepository repository;

    @Test
    public void test1() {
        final List<String> names = Arrays.asList(new String[]{"George","Max"});
        Specification<Account> specification = new Specification<Account>() {
            public Predicate toPredicate(Root<Account> root, CriteriaQuery<?> query, CriteriaBuilder builder) {
                List<Predicate> predicates = new ArrayList<Predicate>();
                predicates.add(root.get("name").in(names).not());
                return builder.and(predicates.toArray(new Predicate[predicates.size()]));
            }
        };
        assertNotNull(repository);
        repository.save(makeAccount("Greg", "123456787", "01-02-01"));
        repository.save(makeAccount("George", "123456788", "01-02-02"));
        repository.save(makeAccount("Max", "123456789", "01-02-03"));

        List<Account> accounts = repository.findAll(specification);
        assertEquals(1,accounts.size());
        assertEquals("123456787",accounts.get(0).getAccountNumber());
    }

    private Account makeAccount(String name, String accountNumber, String sortCode) {
        Account account = new Account();
        account.setName(name);
        account.setAccountNumber(accountNumber);
        account.setSort(sortCode);
        return account;
    }
}

存储库的样子：

@Repository
public interface AccountRepository extends JpaRepository<Account, Long>, JpaSpecificationExecutor<Account> {
}