是否有 JPA/JPQL 查询来搜索在 spring 中作为 JSON 传递的实体子集？

Question

I have two entities defined in spring and I want to query for a post which contains a list of given tags as a subset.

My two entites look like

public class Post {
     private @Id Integer id;
     private @Column String text;
     private @OneToMany List<Tag> tags;
}

and

public class Tag {
    private @Id Integer id;
    private @Column String key;
    private @Column String value;
    private @ManyToOne Post post;
}

I try to implement a query to search for posts containing a set of tags like

@Query("SELECT pst FROM Post pst JOIN pst.tags tgs WHERE :tags MEMBER OF pst.tags")
List<Post> findByTags(@Param("tags") Tag[] tags);

And called it like URL/tags/search/findByTags?tags=[{"key":"test","value":"test"}]

My first problem is that I could not could not get it to accept tag contents instead of tag ids so I tried to solve it like this query

@Query("SELECT post FROM Post pst JOIN post.tags WHERE (SELECT tg from Tag tg WHERE tg.key = :key AND tg.value = :value) MEMBER OF post.tag")
List<Post> findByTags(@Param("key") String key, @Param("value") String value);

And called it like URL/tags/search/findByTags?key=test&value=test which got me following error

Scalar subquery contains more than one row

Is there a way to solve both requirements? It would be a bonus to be able to find all posts which contain a tag by key with any value.

Edit to clarify:

Imagine I have two posts which I will will sketch as JSON including relation for tags.

[
    {
        id: 1,
        text: "text1",
        tags: [
            {
                id: 1,
                key: "key1",
                value: "value1",
            },
            {
                id: 2,
                key: "key2",
                value: "value2",
            },
            {
                id: 3,
                key: "key3",
                value: "value3",
            },
        ],
    },
    {
        id: 2,
        text: "text2",
        tags: [
            {
                id: 4,
                key: "key1",
                value: "value1",
            },
            {
                id: 5,
                key: "key2",
                value: "value2",
            },
        ],
    },
]

And I would like to query for posts with a JSON including information of tags:

[
    {
        key: "key1",
        value: "value1",
    },
    {
        key: "key2",
        value: "value2",
    }
]

So it is necessary that I can query for information of tags which describe a subset of tags in the post, eg more than one key and value pair without having to specify in the query how much parameters I will have and as bonus it would be nice to do all this by using JSON as parameter. So for above query I would get an answer containing both posts.

Answer 1

If you want all posts by tag and value you can try this:

@Query("SELECT pst FROM Post pst JOIN pst.tags tgs WHERE tags.key = :key AND tags.value = :value")
List<Post> findByTags(@Param("key") String key, @Param("value") String value);