如何保持“in"中提供的订单Spring Data JPA 或 Hibernate 中的子句

2022-01-18 00:00:00 java jpql Hibernate spring-data spring-data-jpa

我有一个非常简单的查询，它根据in"子句检索值.作为in"参数出现的列表被适当地排序.

I have a pretty simple query which retrieves values base on "in" clause. List that comes as "in" argument is appropriately sorted.

查询:

@Query(value = "select i from ItemEntity i where i.secondaryId in :ids")
List<ItemEntity> itemsIn(@Param("ids") List<UUID> ids, Pageable pageable);

我需要以与 List<UUID> 相同的方式对结果进行排序.ids，是否有可能在没有普通 sql 的情况下实现这一点，但只能在 Spring Data 和/或 Hibernate 的帮助下实现.

I need results to be ordered the same way as List<UUID> ids, is it possible to achieve this without plain sql but only with the help of Spring Data and/or Hibernate.

推荐答案

你也可以通过 JPA 做到这一点，但你必须按照你想要的顺序创建一个逗号分隔的 id 列表.在您的情况下，您可以保持相同的顺序.

You can do that by JPA too but you will have to create a comma separated list of ids in the order you want. In your case you can keep same order.

@Query(value = "select i from ItemEntity i where i.secondaryId in :ids 
       order by FIND_IN_SET(i.secondaryId, :idStr)")
List<ItemEntity> itemsIn(@Param("ids") List<UUID> ids, @Param("idStr") String idStr);

要创建逗号分隔列表，您可以使用 java 8 流:

To create comma separated list you can java 8 stream:

ids.stream().map(Object::toString).collect(Collectors.joining(","));

例子:

SELECT id FROM User WHERE id in (2,3,1) 
ORDER BY FIND_IN_SET(id,"2,3,1");

结果:

+----+
| id |
+----+
|  2 |
|  3 |
|  1 |
+----+

还有一种使用 JPQL 的替代方法:

There is also one alternative using JPQL:

You can use ,,FIELD'' instead of ,,FIND_IN_SET ''.

您可以在此处找到示例:https://stackoverflow.com/a/65943906/15101302

You can find the example here: https://stackoverflow.com/a/65943906/15101302

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