在 Spring JPA 中編寫自定義查詢

Question

我有兩個實體員工和部門，如下所示：

@Entity
@Table(name="employee")
public class EmployeeDAO implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(unique=true, nullable=false)
    private Long id;

    @Column(name="dept_id")
    private Long deptId;
    ...
}

@Entity
@Table(name="department")
public class DepartmentDAO implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(unique=true, nullable=false)
    private Long id;

    @Column(name="dept_name")
    private String deptName;
    ...
}

每個員工都有一個 id 和一個 deptId（指的是部門 id）。 但是，Employee 和 Department 之間沒有多對一的關系。

我還有一個擴展 JpaRepository 的 EmployeeRepository：

@Repository
public interface EmployeeRepository extends JpaRepository<EmployeeDAO, Long> {
    List<EmployeeDAO> findByDeptId(@Param("deptId") Long deptId);
}

我想要 findByDeptId() 方法做的是，給定一個部門 ID，找到該部門的所有員工以及 deptName 為“default”的部門的所有員工。

我使用@Query編寫了一個自定義查詢，如下所示，但它拋出了錯誤。 我是 JPA 的新手，所以下面的查詢可能是完全錯誤的。

@Query("select emp from EmployeeDAO emp where emp.deptId in ((select dept.id from DepartmentDAO dept where dept.deptName='default'),:deptId))
List<EmployeeDAO> findByDeptId(@Param("deptId") Long deptId);

這是我得到的錯誤：

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'employeeRepository': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Validation failed for query for method public abstract java.util.List EmployeeRepository.findByDeptId(java.lang.Long)!
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1566)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1127)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1051)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:949)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:533)
    ... 31 more
Caused by: java.lang.IllegalArgumentException: Validation failed for query for method public abstract java.util.List EmployeeRepository.findByDeptId(java.lang.Long)!
    at org.springframework.data.jpa.repository.query.SimpleJpaQuery.validateQuery(SimpleJpaQuery.java:87)
    at org.springframework.data.jpa.repository.query.SimpleJpaQuery.<init>(SimpleJpaQuery.java:57)
    at org.springframework.data.jpa.repository.query.JpaQueryFactory.fromMethodWithQueryString(JpaQueryFactory.java:70)
    at org.springframework.data.jpa.repository.query.JpaQueryFactory.fromQueryAnnotation(JpaQueryFactory.java:51)
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$DeclaredQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:137)
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateIfNotFoundQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:202)
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$AbstractQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:80)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.<init>(RepositoryFactorySupport.java:357)
    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:1625)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1562)
    ... 41 more
Caused by: java.lang.NullPointerException
    at org.hibernate.hql.internal.ast.ParameterTranslationsImpl.getNamedParameterExpectedType(ParameterTranslationsImpl.java:92)
    at org.hibernate.engine.query.spi.HQLQueryPlan.buildParameterMetadata(HQLQueryPlan.java:415)
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:150)
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:93)
    at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:167)
    at org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:301)
    at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:236)
    at org.hibernate.internal.SessionImpl.createQuery(SessionImpl.java:1800)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:328)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:344)
    at com.sun.proxy.$Proxy83.createQuery(Unknown Source)
    at org.springframework.data.jpa.repository.query.SimpleJpaQuery.validateQuery(SimpleJpaQuery.java:81)

查詢應該如何？

謝謝。

Answer 1

我認為您應該添加nativeQuery=true 。

代碼如下：

@Query("select emp from EmployeeDAO emp where emp.deptId in ((select dept.id from DepartmentDAO dept where dept.deptName='default'),:deptId)")
List<EmployeeDAO> findByDeptId(@Param("deptId") Long deptId);