是否可以在Spring Repository @Query注释中使用Array对象作为参数？ [英] Is it possible to use an Array object as a parameter in Spring Repository @Query annotation?

问题描述

是否可以在Spring Repository @Query注释中使用Array对象作为参数？

Is it possible to use an Array object as a parameter in Spring Repository @Query annotation?

我正在尝试检索其列节点为表的所有行存在于String数组中。可以使用Spring存储库中的@Query注释一次执行该操作吗？

I'm trying to retrieve all rows in a table whose column node is present in an String array. Is it possible to do it at a time using the @Query annotation in Spring repository?

这是我的位置实体：

@Entity
@Table(name = "LOCATIONS")
public class Location extends Measurement{

    private String latitude;
    private String nsIndicator;

    private String longitude;
    private String ewIndicator;

    @ManyToOne
    @JoinColumn(name="node")
    private Node node;
}

其中节点引用Node类，并且它在数据库中映射为a BIGINT。

Where node references the Node class, and it is mapped in the database as a BIGINT.

我有一个这样的存储库：

I have a repository like this:

public interface LocationRepository extends CrudRepository<Location, Long>{

    @Query(value=
            "SELECT l1.node, l1.id, l1.latitude, l1.longitude " +
            "FROM LOCATIONS l1 WHERE l1.node IN (:ids)", 
            nativeQuery=true)
    List<Location> findMeasureByIds(@Param("ids") String[] ids);
}

您可以看到我正在尝试执行的查询，但是不工作。我不知道是否可以在其中使用数组，或者参数必须只是字符串和/或整数，我在任何地方都找不到。

There you can see the query that I'm trying to execute, but it's not working. I don't know if it's possible to use an array there, or parameters must be just Strings and/or Integers, I couldn't find it anywhere.

ve尝试了几种组合，例如使用具有正确格式或长数组的简单String。.但是到目前为止，仍然没有任何效果。

I've tried several combinations like using a simple String with the right format or a long array.. but nothing has worked so far.

先谢谢了。

解决方案：

@Query(value="SELECT * FROM LOCATIONS l1 " + 
             "INNER JOIN (SELECT node, MAX(id) AS id FROM LOCATIONS GROUP BY node) l2 " + 
             "ON l1.node = l2.node AND l1.id = l2.id " + 
             "WHERE l1.node IN :ids", nativeQuery=true) 
List<Location> findLastLocationByIds(@Param("ids") Set<Long> ids);

我为查询添加了更多功能，因为我需要检索为每个节点插入的最后一行标识符。这样就有了MAX函数和INNER JOIN来完成这项工作。

I've added more functionality to the query because I needed to retrieve the last row inserted for each node identifier. So there's the MAX function and the INNER JOIN to do that work.

推荐答案

使用集合而不是数组（ Set< String> ），并确保它不为空（否则查询将无效。）

Use a collection instead of an array (Set<String>), and make sure it's not empty (otherwise the query will be invalid.

此外，没有理由可以使用本机查询，并且在参数周围不应包含括号：

Also, there's no reason to use a native query for that, and you shouldn't have parentheses around the parameter:

@Query("SELECT l1 FROM Location l1 WHERE l1.node.id IN :ids")
List<Location> findLocationsByNodeIds(@Param("ids") Set<String> ids);

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