如何在Spring中使用@NamedQuery一个CrudRepository @Query？

Question

我想利用@NamedQuery里面的一个JpaRepository.但它不起作用:

public interface MyEntityRepository extends JpaRepository<MyEntity, Long> {
    @Query(name = MyEntity.FIND_ALL_CUSTOM)
    List<MyEntity> findAllCustom(Pageable pageable);
}

@Entity
@NamedQuery(
    name = MyEntity.FIND_ALL_CUSTOM, query = "select * from MyEntity me where me.age >= 18"
)
public class MyEntity {
    public static final String FIND_ALL_CUSTOM = "findAllCustom";
}

结果:

org.springframework.data.mapping.PropertyReferenceException: No property findAllCustom found for type MyEntity!
    at org.springframework.data.mapping.PropertyPath.<init>(PropertyPath.java:75)
    at org.springframework.data.mapping.PropertyPath.create(PropertyPath.java:327)
    at org.springframework.data.mapping.PropertyPath.create(PropertyPath.java:307)
    at org.springframework.data.mapping.PropertyPath.from(PropertyPath.java:270)
    at org.springframework.data.mapping.PropertyPath.from(PropertyPath.java:241)
    at org.springframework.data.repository.query.parser.Part.<init>(Part.java:76)
    at org.springframework.data.repository.query.parser.PartTree$OrPart.<init>(PartTree.java:235)
    at org.springframework.data.repository.query.parser.PartTree$Predicate.buildTree(PartTree.java:373)
    at org.springframework.data.repository.query.parser.PartTree$Predicate.<init>(PartTree.java:353)
    at org.springframework.data.repository.query.parser.PartTree.<init>(PartTree.java:84)
    at org.springframework.data.jpa.repository.query.PartTreeJpaQuery.<init>(PartTreeJpaQuery.java:61)
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:94)
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateIfNotFoundQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:205)
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$AbstractQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:72)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.<init>(RepositoryFactorySupport.java:369)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:192)
    at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.initAndReturn(RepositoryFactoryBeanSupport.java:239)
    at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:225)
    at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet(JpaRepositoryFactoryBean.java:92)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1633)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1570)
    ... 28 more

---

更新:

public interface MyEntityRepository extends JpaRepository<MyEntity, Long> {
    List<MyEntity> findAllCustom(Pageable pageable);
}

@Entity
@NamedQuery(
    name = "MyEntity.findAllCustom", query = "select * from MyEntity me where me.age >= 18"
)
public class MyEntity {

}

还是同样的例外:

PropertyReferenceException: No property findAllCustom found for type MyEntity!

Answer 1

看一下Spring Data JPA 的文档 - 使用JPA NamedQueries.

我建议您遵循文档中设置的约定(从配置的域类的简单名称开始,后跟由点分隔的方法名称).剪切下划线并将查询命名为

@NamedQuery(name = "MyEntity.findAllCustom", query="...")

甚至更好地添加一个暗示名称,如findByAge或某事.

要允许执行这些命名查询,您需要做的就是按如下方式指定MyEntityRepository:

public interface MyEntityRepository extends JpaRepository <MyEntity, Long> {
    List<MyEntity> findAllCustom();
}

我用JpaRepository文档举例说明了它.但你可以尝试简单CrudRepository,看看是否有效.

我认为问题在于您使用@Query和查询方法的查询优先于使用@NamedQuery定义的查询.阅读@Query用法的文档,我想你在哪里也错了.

更新 要使用Pageable,根据这个答案

要应用分页,必须派生第二个子查询.因为子查询指的是相同的字段,所以您需要确保查询对其引用的实体/表使用别名

这意味着你会像你一样重写你的查询 query ="select * from MyEntity me where me.age >= 18".

该示例用于@Query,但这也是一个命名查询,所以它也应该适用于您的情况.唯一的区别是,@Query您实际上直接绑定它们而不是将它们注释到域类.

更新2

我尝试了自己的应用程序.首先,您应该使用别名而不是*(ie me)进行查询.其次,您使用的字符串FIND_ALL_CUSTOM 不遵循"MyEntity.findAllCustom"的约定.

解

复制粘贴:

public interface MyEntityRepository extends JpaRepository<MyEntity, Long> {
    List<MyEntity> findAllCustom(Pageable pageable);
    List<MyEntity> findAllCustom();
}

@Entity
@NamedQuery(
    name = MyEntity.FIND_ALL_CUSTOM, query = "select me from MyEntity me where me.age >= 18"
)
public class MyEntity {
    public static final String FIND_ALL_CUSTOM = "MyEntity.findAllCustom";
}

两者都有效.对于具有可分页方法参数的那个,将其称为myEntityRepository.allCustom(new PageRequest(0,20)).Ofc,你知道myEntityRepository是注入的.