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如何刪除實體聯接使用JPA和Hibernate

2017-06-13 66 views
8

我有以下實體：如何刪除實體聯接使用JPA和Hibernate

enter image description here

我想通過ID和使用JPA的用戶的用戶名刪除WordSet。

這裏是實體聲明：

用戶

@Entity 
@Data 
@ToString(callSuper = true) 
@EqualsAndHashCode(callSuper = true) 
@AllArgsConstructor 
@NoArgsConstructor 
public class User extends AbstractModelClass { 

    private String name; 
    private String username; 
    private String password; 
    private String email; 

    @ManyToMany(fetch = FetchType.EAGER) 
    private Set<Role> roles; 
}

UserDictionary

@Entity 
@Data 
@ToString(callSuper = true) 
@EqualsAndHashCode(callSuper = true) 
@AllArgsConstructor 
@NoArgsConstructor 
public class UserDictionary extends AbstractModelClass { 

    @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, mappedBy = "userDictionary") 
    private Set<WordSet> wordSets; 

    @OneToOne(cascade = CascadeType.ALL) 
    private User user; 

    @PrePersist 
    private void addDictionaryToWordSets() { 
     wordSets.forEach(wordSet -> wordSet.setUserDictionary(this)); 
    } 
}

WordSet

@Entity 
@Data 
@AllArgsConstructor 
@NoArgsConstructor 
@EqualsAndHashCode(callSuper = true, exclude = {"studiedWords", "userDictionary"}) 
@ToString(callSuper = true, exclude = {"studiedWords", "userDictionary"}) 
public class WordSet extends AbstractModelClass { 

    @NotBlank 
    private String name; 

    @NotBlank 
    private String description; 

    @ManyToMany(fetch = FetchType.EAGER, cascade = {CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REMOVE}) 
    private List<StudiedWord> studiedWords; 

    @ManyToOne(fetch = FetchType.EAGER) 
    private UserDictionary userDictionary; 

    public WordSet(String name, String description, List<StudiedWord> studiedWords) { 
     this.name = name; 
     this.description = description; 
     this.studiedWords = studiedWords; 
    } 

    public WordSet(Long id, String name, String description, List<StudiedWord> studiedWords) { 
     super(id); 
     this.name = name; 
     this.description = description; 
     this.studiedWords = studiedWords; 
    } 

    @PreRemove 
    private void removeFromUserDictionary() { 
     userDictionary.getWordSets().removeIf(this::equals); 
    } 
}

這裏是我的WordSetDao的一部分：

@Override 
public Optional<WordSet> findByIdAndUsername(long id, String username) { 
    return findOrEmpty(() -> entityManager.createQuery(
      "SELECT w FROM WordSet w " + 
        "WHERE w.userDictionary.user.username = :username AND w.id = :id", WordSet.class) 
              .setParameter("id", id) 
              .setParameter("username", username) 
              .getSingleResult()); 
} 

@Override 
public void deleteByIdAndUsername(long id, String username) { 
    entityManager.createQuery(
      "DELETE FROM WordSet w WHERE w.userDictionary.user.username = :username AND w.id = :id") 
       .setParameter("id", id) 
       .setParameter("username", username) 
       .executeUpdate(); 
}

findByIdAndUsername工作正常，但刪除拋出以下異常：

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.dao.InvalidDataAccessResourceUsageException: could not prepare statement; SQL [/* delete FKs in join table */ delete from word_set_studied_words where (word_set_id) in (select id from word_set where username=? and id=?)]; nested exception is org.hibernate.exception.SQLGrammarException: could not prepare statement 

    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:982) 
    at org.springframework.web.servlet.FrameworkServlet.doDelete(FrameworkServlet.java:894) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:654) 
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) 
    at org.springframework.test.web.servlet.TestDispatcherServlet.service(TestDispatcherServlet.java:65) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) 
    at org.springframework.mock.web.MockFilterChain$ServletFilterProxy.doFilter(MockFilterChain.java:167) 
    at org.springframework.mock.web.MockFilterChain.doFilter(MockFilterChain.java:134) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:317) 
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:127) 
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:91) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) 
    at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:115) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) 
    at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) 
    at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) 
    at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:169) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) 
    at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) 
    at io.github.solomkinmv.glossary.web.security.auth.JwtTokenAuthenticationProcessingFilter.successfulAuthentication(JwtTokenAuthenticationProcessingFilter.java:58) 
    at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:240) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) 
    at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:121) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) 
    at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:66) 
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) 
    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) 
    at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56) 
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331) 
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:214) 
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:177) 
    at org.springframework.mock.web.MockFilterChain.doFilter(MockFilterChain.java:134) 
    at org.springframework.test.web.servlet.MockMvc.perform(MockMvc.java:155) 
    at io.github.solomkinmv.glossary.web.controller.WordSetControllerTest.deleteWordSet(WordSetControllerTest.java:236) 
    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:498) 
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50) 
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) 
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47) 
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) 
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26) 
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75) 
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86) 
    at org.springframework.restdocs.JUnitRestDocumentation$1.evaluate(JUnitRestDocumentation.java:55) 
    at org.junit.rules.RunRules.evaluate(RunRules.java:20) 
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84) 
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325) 
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:252) 
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94) 
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) 
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) 
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) 
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) 
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) 
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) 
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70) 
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363) 
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191) 
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137) 
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68) 
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51) 
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242) 
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70) 
Caused by: org.springframework.dao.InvalidDataAccessResourceUsageException: could not prepare statement; SQL [/* delete FKs in join table */ delete from word_set_studied_words where (word_set_id) in (select id from word_set where username=? and id=?)]; nested exception is org.hibernate.exception.SQLGrammarException: could not prepare statement 
    at org.springframework.orm.jpa.vendor.HibernateJpaDialect.convertHibernateAccessException(HibernateJpaDialect.java:261) 
    at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:244) 
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:491) 
    at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:59) 
    at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213) 
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:147) 
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) 
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:656) 
    at io.github.solomkinmv.glossary.persistence.dao.impl.WordSetJpaDao$$EnhancerBySpringCGLIB$$48825a47.deleteByIdAndUsername(<generated>) 
    at io.github.solomkinmv.glossary.service.domain.impl.WordSetServiceImpl.deleteByIdAndUsername(WordSetServiceImpl.java:128) 
    at io.github.solomkinmv.glossary.service.domain.impl.WordSetServiceImpl$$FastClassBySpringCGLIB$$c3da160a.invoke(<generated>) 
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) 
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:721) 
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) 
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) 
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282) 
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) 
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) 
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:656) 
    at io.github.solomkinmv.glossary.service.domain.impl.WordSetServiceImpl$$EnhancerBySpringCGLIB$$4b4a0f55.deleteByIdAndUsername(<generated>) 
    at io.github.solomkinmv.glossary.web.controller.WordSetController.deleteWordSet(WordSetController.java:79) 
    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:498) 
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:220) 
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:134) 
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:116) 
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) 
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) 
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) 
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963) 
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897) 
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) 
    ... 70 more 
Caused by: org.hibernate.exception.SQLGrammarException: could not prepare statement 
    at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:106) 
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42) 
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:109) 
    at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:182) 
    at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareStatement(StatementPreparerImpl.java:78) 
    at org.hibernate.hql.internal.ast.exec.BasicExecutor.doExecute(BasicExecutor.java:78) 
    at org.hibernate.hql.internal.ast.exec.DeleteExecutor.execute(DeleteExecutor.java:107) 
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.executeUpdate(QueryTranslatorImpl.java:429) 
    at org.hibernate.engine.query.spi.HQLQueryPlan.performExecuteUpdate(HQLQueryPlan.java:374) 
    at org.hibernate.internal.SessionImpl.executeUpdate(SessionImpl.java:1348) 
    at org.hibernate.internal.QueryImpl.executeUpdate(QueryImpl.java:102) 
    at org.hibernate.jpa.internal.QueryImpl.internalExecuteUpdate(QueryImpl.java:405) 
    at org.hibernate.jpa.spi.AbstractQueryImpl.executeUpdate(AbstractQueryImpl.java:61) 
    at io.github.solomkinmv.glossary.persistence.dao.impl.WordSetJpaDao.deleteByIdAndUsername(WordSetJpaDao.java:50) 
    at io.github.solomkinmv.glossary.persistence.dao.impl.WordSetJpaDao$$FastClassBySpringCGLIB$$3577673c.invoke(<generated>) 
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) 
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:721) 
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) 
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) 
    ... 98 more 
Caused by: org.h2.jdbc.JdbcSQLException: Column "USERNAME" not found; SQL statement: 
/* delete FKs in join table */ delete from word_set_studied_words where (word_set_id) in (select id from word_set where username=? and id=?) [42122-193] 
    at org.h2.message.DbException.getJdbcSQLException(DbException.java:345) 
    at org.h2.message.DbException.get(DbException.java:179) 
    at org.h2.message.DbException.get(DbException.java:155) 
    at org.h2.expression.ExpressionColumn.optimize(ExpressionColumn.java:147) 
    at org.h2.expression.Comparison.optimize(Comparison.java:178) 
    at org.h2.expression.ConditionAndOr.optimize(ConditionAndOr.java:130) 
    at org.h2.command.dml.Select.prepare(Select.java:856) 
    at org.h2.engine.Session.optimizeQueryExpression(Session.java:233) 
    at org.h2.expression.ConditionInSelect.optimize(ConditionInSelect.java:117) 
    at org.h2.command.dml.Delete.prepare(Delete.java:131) 
    at org.h2.command.Parser.prepareCommand(Parser.java:259) 
    at org.h2.engine.Session.prepareLocal(Session.java:561) 
    at org.h2.engine.Session.prepareCommand(Session.java:502) 
    at org.h2.jdbc.JdbcConnection.prepareCommand(JdbcConnection.java:1203) 
    at org.h2.jdbc.JdbcPreparedStatement.<init>(JdbcPreparedStatement.java:73) 
    at org.h2.jdbc.JdbcConnection.prepareStatement(JdbcConnection.java:287) 
    at sun.reflect.GeneratedMethodAccessor93.invoke(Unknown Source) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
    at java.lang.reflect.Method.invoke(Method.java:498) 
    at org.apache.tomcat.jdbc.pool.ProxyConnection.invoke(ProxyConnection.java:126) 
    at org.apache.tomcat.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:108) 
    at org.apache.tomcat.jdbc.pool.DisposableConnectionFacade.invoke(DisposableConnectionFacade.java:81) 
    at com.sun.proxy.$Proxy87.prepareStatement(Unknown Source) 
    at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$1.doPrepare(StatementPreparerImpl.java:87) 
    at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:172) 
    ... 113 more

此外，而不是

DELETE FROM WordSet w WHERE w.userDictionary.user.username = :username AND w.id = :id

我已經試過以下查詢：

DELETE FROM WordSet w 
WHERE w IN 
    (SELECT ws FROM UserDictionary u 
    JOIN u.wordSets ws 
    WHERE u.user.username = :username AND ws.id = :id)

和它的作品在我的H2數據庫，但未能在MySQL具有以下情況除外：

java.sql.SQLException: You can't specify target table 'word_set' for update in FROM clause 
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:964) ~[mysql-connector-java-5.1.40.jar!/:5.1.40] 
    ...

我GOOGLE了有關子查詢和MySQL（one，two），但無法找到如何使用JPA製作這樣的技巧。

那麼，如何刪除wordset？我的實體映射有問題嗎？

這裏是我的DB模式，它看起來是正確的：

enter image description here

來源

2017-06-13 solomkinmv

回答

7

有一些很多事情是錯的映射：

  1. 使用預先抓取每一個集合類型甚至更多的是你目前的問題。您實際上是通過任何給定的查詢獲取整個數據庫。 Switch to LAZY as explained in this article。

  2. 你說它爲H2，但事實並非如此：

    Caused by: org.h2.jdbc.JdbcSQLException: Column "USERNAME" not found; SQL statement: 
/* delete FKs in join table */ delete from word_set_studied_words where (word_set_id) in (select id from word_set where username=? and id=?) [42122-193] 
at org.h2.message.DbException.getJdbcSQLException(DbException.java:345)

  3. 這種類型的查詢不被MySQL支持：

    DELETE FROM WordSet w 
WHERE w IN 
(SELECT ws FROM UserDictionary u 
JOIN u.wordSets ws 
WHERE u.user.username = :username AND ws.id = :id)
  4. 連接被禁止散裝報表中的說明Hibernate User Guide。
  5. 現在，根據要刪除的條目數量，batch delete可能是更好的方法，因爲您可以防止lost update anomaly。
  6. 您在這裏有一個互連實體的圖形，因此批量刪除可能無法幫助您，因爲您無法首先刪除父級記錄而無需刪除子級關聯。

來源

2017-06-16 12:09:37

+0

1.謝謝，我知道這一點。它只是一個測試項目:) 2.當我說它適用於H2我的意思是第二個查詢嵌套'選擇' 3.我認爲可能有一些技巧用一個多選擇語句包裝嵌套選擇，但我可以用JPQL來做到這一點。 – solomkinmv

+0

你說這個映射有很多錯誤。除了獲取策略之外還有什麼不對嗎？ – solomkinmv

0

值java.sql.SQLException：您不能指定目標表 'word_set' 在FROM子句 在 更新COM .mysql.jdbc.SQLError.createSQLException（SQLError.java:964）〜[！使用mysql-connector-java的5.1.40.jar /：5.1.40]

此異常造成的，因爲在MySQL你不能修改/刪除您在SELECT部分​​中使用的同一個表格。這裏記錄了這種行爲https://dev.mysql.com/doc/refman/5.6/en/update.html。嵌套子查詢深入FROM子句或2）加入該表到自身的解決方案1）

來源

2017-06-13 21:20:52

+0

是的，我見過它。你能寫一個例子如何使用JPQL（最好是第二）做第一或第二種情況？ – solomkinmv

0

你有沒有試圖定期加入刪除？還有一個類似的問題在這裏： Delete with Join in MySQL

...雖然不是通過JPA，但有一個基於連接刪除的接受的答案，顯示和例子，但它似乎MySQL的具體。

訣竅是在delete子句本身中指定實際的表，而不是在通過JOIN引用其他表時引用from子句。

我現在還沒有設置測試JPA針對mysql。 JQL可能無法適應這種情況，但您可以使用本機查詢來完成此操作。

來源

2017-06-21 17:14:25 slambeth

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