spring-data-jdbc: JdbcQueryCreator: 无法按嵌套实体查询

spring-data-jdbc: JdbcQueryCreator: Cannot query by nested entity

我正在使用 Spring Boot 创建服务(第一次使用 Spring)。我在数据库中有一个由三元组 (mission, cycle, id) 标识的实体,这在逻辑上是主键。
为了解决 Spring-data-jdbc 具有 @Id Long 主键的要求,我创建了一个 IDENTITY 主键并为这些添加了 UNIQUE 约束列。在我的实验中,我有两个 table 以这种方式键入(第二个在逻辑键中有一个附加列):

CREATE TABLE IF NOT EXISTS submission_counter (
    id IDENTITY NOT NULL PRIMARY KEY,
    mission VARCHAR(10) NOT NULL,
    cycle INTEGER NOT NULL,
    proposal_id INTEGER NOT NULL,
    count INTEGER NOT NULL DEFAULT 1,
    UNIQUE (mission, proposal_id, cycle),
    CHECK (count >= 1),
    CHECK (proposal_id >= 1)
);

CREATE TABLE IF NOT EXISTS submission (
    id IDENTITY NOT NULL PRIMARY KEY,
    mission VARCHAR(10) NOT NULL,
    cycle INTEGER NOT NULL,
    proposal_id INTEGER NOT NULL,
    number INTEGER NOT NULL,
    CHECK (number >= 1),
    CHECK (proposal_id >= 1),
    UNIQUE (mission, cycle, proposal_id, number)
);

为了在 Java 代码中打包密钥三元组,我为两个实体 类 创建了一个嵌入式记录。

enum Mission {A, B, C}
public record SubmissionCount(int count){}
public record ProposalId(int id) {}
public record SubmissionNumber(int number) {}
public record SubmissionKey(Mission mission, Cycle cycle, ProposalId proposalId) {}
public record Submission(@Id Long id, SubmissionKey key, SubmissionNumber number) {}
public record SubmissionCounter(@Id Long id,  SubmissionKey key, SubmissionCount count) {}

以前,我将所有 SubmissionKey 字段内联在使用它们的记录中,并且一切正常。现在,当尝试为密钥编写查询时,我从 JdbcQueryCreator

得到一个异常

此存储库定义结果“无法按嵌套实体查询”:

public interface SubmissionRepository extends CrudRepository<Submission, Long> {
    Streamable<Submission> findByKey(SubmissionKey key);
}
Caused by: java.lang.IllegalArgumentException: Cannot query by nested entity: key
    at org.springframework.data.jdbc.repository.query.JdbcQueryCreator.validateProperty(JdbcQueryCreator.java:147)

我试过用多种方式编写存储库查询方法。我最近的尝试是基于一些问题说方法名可以做字段导航。

public interface SubmissionCounterRepository extends CrudRepository<SubmissionCounter, Long> {
    Optional<SubmissionCounter> findByKeyMissionAndKeyCycleAndKeyProposalId(SubmissionKey key);
}

这导致

Caused by: java.lang.IllegalStateException: Query method expects at least 2 arguments but only found 1. This leaves an operator of type SIMPLE_PROPERTY for property key.cycle unbound.
    at org.springframework.data.relational.repository.query.RelationalQueryCreator.throwExceptionOnArgumentMismatch(RelationalQueryCreator.java:126)
    at org.springframework.data.relational.repository.query.RelationalQueryCreator.validate(RelationalQueryCreator.java:110)
    at org.springframework.data.jdbc.repository.query.JdbcQueryCreator.validate(JdbcQueryCreator.java:117)

如果我手动滚动所有内容,我会将 (mission, cycle, proposal_id) 三元组仅放在 submission_counter table 中,并将其与 submission 结合起来进行读取。

Spring有更好的方法吗?我可以使用 @Query 和命名参数进行字段导航吗?

几天后回过头来,问题是 SubmissionKey 元素上缺少 @Embedded 注释。

像这样添加 @Embedded 解决了问题:

public record Submission(@Id Long id, @Embedded(onEmpty = Embedded.OnEmpty.USE_EMPTY) SubmissionKey key, SubmissionNumber number) {}

public record SubmissionCounter(@Id Long id,  @Embedded(onEmpty = USE_EMPTY) SubmissionKey key, SubmissionCount count) {}

这让我可以在我的存储库接口上定义 findByKey 方法,并且可以正确派生查询:

public interface SubmissionRepository extends CrudRepository<Submission, Long> {
    Streamable<Submission> findByKey(SubmissionKey key);
}

public interface SubmissionCounterRepository extends CrudRepository<SubmissionCounter, Long> {
    Optional<SubmissionCounter> findByKey(SubmissionKey key);
}

我认为“无法通过嵌套实体查询”的错误意味着 Spring JDBC 得出的结论是 SubmissionKey 是嵌套在 Submission 实体中的单独实体.事后看来很明显。