问题
I'm trying to make a very simple JPQL using a join but I'm having zero success. I want to get the most recent log in date of a user, given a user id. I am using Spring Data JPA + Hibernate.
I have a MySQL database which contains the table Activity:
@Table(name = "activity")
@SuppressWarnings("serial")
public class Activity implements Serializable {
@Id
@GeneratedValue
private Long id;
@Column(name = "date", insertable = true, nullable = false, updatable = false)
@Temporal(TemporalType.TIMESTAMP)
private Date date;
@Column(insertable = true, name = "organization_id", nullable = true, updatable = true, unique = false)
@Basic(optional = true)
private Long organizationId;
@Column(insertable = true, name = "operation", nullable = false, updatable = true, unique = false)
@Basic(optional = false)
private String operation;
//getters and setters
}
It contains a number of other tables including LoginAttempt:
@Table(name = "login_attempt")
@SuppressWarnings("serial")
public class LoginAttempt implements Serializable{
@Id
@GeneratedValue
private Long id;
@OneToOne(fetch = FetchType.EAGER, optional = false)
@Basic(optional = false)
@JoinColumn(name = "activity_id", insertable = true, nullable = false, unique = false, updatable = false)
private Activity activity;
@Column(insertable = true, name = "user_id", nullable = true, updatable = true, unique = false)
@Basic(optional = true)
private Long userId;
@Column(insertable = true, name = "user_email", nullable = true, updatable = true, unique = false)
@Basic(optional = true)
private String userEmail;
@Column(insertable = true, name = "login_successful", nullable = false, updatable = true, unique = false)
@Basic(optional = false)
private boolean loginSuccessful;
//getters and setters
}
All other tables reference Activity using a column called "activity_id".
This is my DAO with one method and the @Query annotation.
public interface MyDAO extends JpaRepository<Activity, Long> {
@Query("SELECT a FROM Activity a, LoginAttempt la JOIN a.id la WHERE la.user_email = (:userId) AND a.date = (SELECT MAX(a.date))")
public Activity findMostRecentLoginForUser(@Param("userId") Long userId);
}
When I have a simple select all statement in the @Query it works, so I'm connecting to the database correctly and am able to get everything back. I was getting a lot of validation errors on my query at first but now I'm getting the following (partial stacktrace).
Caused by: java.lang.IllegalArgumentException: Validation failed for query for method public abstract com.domain.Activity com.dao.MyDAO.findMostRecentLoginForUser(java.lang.Long)!
at org.springframework.data.jpa.repository.query.SimpleJpaQuery.validateQuery(SimpleJpaQuery.java:97)
at org.springframework.data.jpa.repository.query.SimpleJpaQuery.<init>(SimpleJpaQuery.java:66)
at org.springframework.data.jpa.repository.query.SimpleJpaQuery.fromQueryAnnotation(SimpleJpaQuery.java:169)
at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$DeclaredQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:114)
at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateIfNotFoundQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:160)
at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$AbstractQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:68)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.<init>(RepositoryFactorySupport.java:290)
at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:158)
at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.getObject(RepositoryFactoryBeanSupport.java:162)
at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.getObject(RepositoryFactoryBeanSupport.java:44)
at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:142)
... 44 more
Caused by: java.lang.NullPointerException
at org.hibernate.hql.internal.ast.HqlSqlWalker.createFromJoinElement(HqlSqlWalker.java:393)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.joinElement(HqlSqlBaseWalker.java:3645)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3431)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3309)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:706)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:562)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:299)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:247)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:250)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:185)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:138)
at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:105)
at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:80)
at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:168)
at org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:221)
at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:199)
at org.hibernate.internal.SessionImpl.createQuery(SessionImpl.java:1778)
at org.hibernate.ejb.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:291)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:366)
at com.sun.proxy.$Proxy33.createQuery(Unknown Source)
at org.springframework.data.jpa.repository.query.SimpleJpaQuery.validateQuery(SimpleJpaQuery.java:91)
... 54 more
My brain is fried and I can't get my head round any of the examples I've read. Any help is appreciated. Thanks.
回答1:
Your query is malformed--its subquery doesn't specify what it's selecting from. Also, since you have a direct reference from LoginAttempt to Activity, you don't need to do any explicit joins. Try something like this (untested):
SELECT la.activity FROM LoginAttempt la
WHERE la.user_email = :userId
AND la.activity.date = (SELECT MAX(la2.activity.date) FROM LoginAttempt la2
WHERE la2.user_email = :userId)
The subquery selects the most-recent date for the given user. The outer query selects the Activity for the given user and whose date is the result of the subquery.
来源：https://stackoverflow.com/questions/19733877/jpql-join-queries