Question

长话短说：

这是优惠券系统。实体是公司，客户，优惠券。 公司生成优惠券。每个公司都以 MANY（coupon）_To_ONE（company）关系拥有自己的优惠券集合。任何客户都可以购买任何优惠券。这反映了 MANY（客户）_To_MANY（优惠券）关系。

任何优惠券都可以删除。创建它的公司决定删除它，或者EndDate被传递并由每日线程自动删除。应该发生什么：一旦删除-创建它的公司-不再拥有它，任何购买它的客户-不再拥有它，并且它的记录应该完全消失。

在实践中：我可以手动删除优惠券，如果没有客户持有，则可以自动删除优惠券。但是，如果客户持有优惠券，而我尝试删除此优惠券，则会收到错误消息：

org.apache.derby.client.am.SqlException: DELETE on table 'COUPON' caused a violation of foreign key constraint 'FKPPNDQDPYDMSUMC9YQSLM5HSS4' for key (21).  The statement has been rolled back.
    at org.apache.derby.client.am.ClientStatement.completeExecute(Unknown Source) ~[derbyclient-10.11.1.1.jar:na]
    at org.apache.derby.client.net.NetStatementReply.parseEXCSQLSTTreply(Unknown Source) ~[derbyclient-10.11.1.1.jar:na]
    at org.apache.derby.client.net.NetStatementReply.readExecute(Unknown Source) ~[derbyclient-10.11.1.1.jar:na]
    at org.apache.derby.client.net.StatementReply.readExecute(Unknown Source) ~[derbyclient-10.11.1.1.jar:na]
    at org.apache.derby.client.net.NetPreparedStatement.readExecute_(Unknown Source) ~[derbyclient-10.11.1.1.jar:na]
    at org.apache.derby.client.am.ClientPreparedStatement.readExecute(Unknown Source) ~[derbyclient-10.11.1.1.jar:na]
    at org.apache.derby.client.am.ClientPreparedStatement.flowExecute(Unknown Source) ~[derbyclient-10.11.1.1.jar:na]
    at org.apache.derby.client.am.ClientPreparedStatement.executeUpdateX(Unknown Source) ~[derbyclient-10.11.1.1.jar:na]
    at org.apache.derby.client.am.ClientPreparedStatement.executeUpdate(Unknown Source) ~[derbyclient-10.11.1.1.jar:na]
    at com.zaxxer.hikari.pool.ProxyPreparedStatement.executeUpdate(ProxyPreparedStatement.java:61) ~[HikariCP-2.7.9.jar:na]
    at com.zaxxer.hikari.pool.HikariProxyPreparedStatement.executeUpdate(HikariProxyPreparedStatement.java) ~[HikariCP-2.7.9.jar:na]
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:175) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.engine.jdbc.batch.internal.NonBatchingBatch.addToBatch(NonBatchingBatch.java:45) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.persister.entity.AbstractEntityPersister.delete(AbstractEntityPersister.java:3339) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.persister.entity.AbstractEntityPersister.delete(AbstractEntityPersister.java:3596) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.action.internal.EntityDeleteAction.execute(EntityDeleteAction.java:99) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:600) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:474) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:337) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:39) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1437) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:494) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3245) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2451) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:473) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:156) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$100(JdbcResourceLocalTransactionCoordinatorImpl.java:38) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:231) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:68) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
    at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:536) ~[spring-orm-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:746) ~[spring-tx-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:714) ~[spring-tx-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:532) ~[spring-tx-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:304) ~[spring-tx-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98) ~[spring-tx-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139) ~[spring-tx-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:135) ~[spring-data-jpa-2.0.9.RELEASE.jar:2.0.9.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61) ~[spring-data-commons-2.0.9.RELEASE.jar:2.0.9.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at com.sun.proxy.$Proxy98.delete(Unknown Source) ~[na:na]
    at cs5.services.CompanyFacade.removeCoupon(CompanyFacade.java:103) ~[classes/:na]
    at cs5.controllers.CompanyController.removeCoupon(CompanyController.java:55) ~[classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_171]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_171]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_171]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_171]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:877) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at cs5.filters.SessionFilter.doFilter(SessionFilter.java:43) ~[classes/:na]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:800) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1471) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [na:1.8.0_171]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [na:1.8.0_171]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at java.lang.Thread.run(Unknown Source) [na:1.8.0_171]

CompanyFacade （保留Company的所有业务逻辑，验证信息并调用JpaRepository方法）removeCoupon（）：

public void removeCoupon(Coupon coupon) throws ConnectionPoolException, DAOException, CouponDontExistException {
    if (couponDao.getOne(coupon.getId()) != null) {
        couponDao.delete(coupon);
    } else {
        throw new CouponDontExistException(
                "Failed to remove Coupon. coupon with id " + coupon.getId() + " cannot be found;");
    }
}

优惠券（定义与COMPANY的关系）

@Entity
public class Coupon {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;
    private String title;
    @Column(name = "startDate")
    private Date startDate;
    @Column(name = "endDate")
    private Date endDate;
    private int amount;
    private CouponType type;
    private String message;
    private double price;
    private String image;
    @ManyToOne(fetch = FetchType.LAZY, optional = false)
    @JoinColumn(name = "company_id", nullable = false)
    @OnDelete(action = OnDeleteAction.CASCADE)
    @JsonIgnore
    private Company company;

公司

@Entity
public class Company {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;
    @Column(unique = true)
    private String compName;
    private String password;
    private String email;

客户（定义与COUPON的关系）

@Entity
public class Customer {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;
    @Column(unique = true)
    private String custName;
    private String password;
    @ManyToMany(fetch = FetchType.LAZY)
    @JoinTable(name = "CUSTOMER_COUPON", joinColumns = @JoinColumn(name = "customerId"), inverseJoinColumns = @JoinColumn(name = "couponId"))
    private Set<Coupon> coupons;

我想念什么？其他一切工作都很好。您的建议将不胜感激。

Answer 1

从我的角度来看，你有一个

@OnDelete（action = OnDeleteAction.CASCADE）

在Coupon定义内，在此不需要。但这在“客户与多对多”关系中是必需的。那是因为当您删除优惠券时，关系将转到公司，因此这里不需要删除级联。

当客户持有优惠券的多对多引用时，您需要级联删除，或者必须先删除m-2-m关系，然后才能删除优惠券。

Answer 2

已解决： 我发现，既然在客户实体上定义了ManyToMany认证，并且现成的休眠JPA接口在这里将不会有用，所以我必须编写自己的自定义查询：

String query = "DELETE FROM customer_coupon WHERE coupon_id = ";
query += coupon.getId();

事实证明这很困难，因为JPArepository将不接受这种本机SQL，而我无法弄清它的JPQL语法，或者它是完全不可能的：不断出现customer_coupon表未映射的异常（尽管它确实存在））。

由于这个原因，我必须找到一种使用spring的 EntityManager 的方法，并通过可能需要它们的每个JPA操作直接在数据库上执行自定义查询。为此，我编写了一个带有显式方法的实用程序存储库类。这可以解决问题：

@Service
public class UtilRespository {

    @PersistenceContext
    private EntityManager em;

    @Transactional
    public int removeCouponOwnership(Coupon coupon) {
        String query = "DELETE FROM customer_coupon WHERE coupon_id = ";
        query += coupon.getId();

        Query q = em.createNativeQuery(query);
        int removed = q.executeUpdate();
        em.close();
        System.out.println("Successfully removed Coupon " + coupon.getId() + " from " + removed + " customers;");
        return removed;
    }
}

SqlException：对表'COUPON'的DELETE违反了外键约束

长话短说：

2 个答案: