我是Spring和Hibernate的新手，并且尝试了所有可能无法解决的问题。任何帮助将不胜感激。我目前正在看书中的一个示例项目，并且收到一条错误消息：“ GenerationTarget遇到异常接受命令：通过JDBC语句执行DDL错误。”我正在使用MariaDB数据库，而我的休眠方言是org.hibernate.dialect.MySQL5InnoDBDialect。
导致此问题的查询是
alter table car drop foreign key FK2mqqwvxtowv4vddvtsmvtiqa2;
如果我尝试直接在数据库中运行此查询，它将运行正常。我已将ddl-auto属性设置为create-drop，所以也许当car表被删除并且不在时，它正在尝试执行此查询？我不确定为什么会这样做，或者如果出现问题就如何关闭此行为。
如果我将ddl-auto更改为验证或更新，则该应用程序将完全无法运行。如果我将其更改为create，它可以正常工作，并且不会出现错误。
通过create-drop，应用程序确实连接到数据库，并且创建了我的所有表。这些表仍然按原样定义，但错误仍然存在。
控制台输出：
2018-07-25 16:56:24.229 INFO 12414 --- [ restartedMain] c.p.cardatabase.CardatabaseApplication : Starting CardatabaseApplication on Northstar-2.local with PID 12414 2018-07-25 16:56:24.230 INFO 12414 --- [ restartedMain] c.p.cardatabase.CardatabaseApplication : No active profile set, falling back to default profiles: default
2018-07-25 16:56:24.278 INFO 12414 --- [ restartedMain] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@42e3f007: startup date [Wed Jul 25 16:56:24 AKDT 2018]; root of context hierarchy
2018-07-25 16:56:25.134 INFO 12414 --- [ restartedMain] o.s.b.f.s.DefaultListableBeanFactory : Overriding bean definition for bean 'httpRequestHandlerAdapter' with a different definition: replacing [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$EnableWebMvcConfiguration; factoryMethodName=httpRequestHandlerAdapter; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]] with [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.data.rest.webmvc.config.RepositoryRestMvcConfiguration; factoryMethodName=httpRequestHandlerAdapter; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/data/rest/webmvc/config/RepositoryRestMvcConfiguration.class]]
2018-07-25 16:56:25.535 INFO 12414 --- [ restartedMain] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration' of type [org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration$$EnhancerBySpringCGLIB$$e5303d26] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2018-07-25 16:56:25.850 INFO 12414 --- [ restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2018-07-25 16:56:25.875 INFO 12414 --- [ restartedMain] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2018-07-25 16:56:25.875 INFO 12414 --- [ restartedMain] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.29
2018-07-25 16:56:25.883 INFO 12414 --- [ost-startStop-1] o.a.catalina.core.AprLifecycleListener : The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/Users/tatiana/Library/Java/Extensions:/Library/Java/Extensions:/Network/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java:.]
2018-07-25 16:56:26.025 INFO 12414 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2018-07-25 16:56:26.025 INFO 12414 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1750 ms
2018-07-25 16:56:26.155 INFO 12414 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2018-07-25 16:56:26.156 INFO 12414 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2018-07-25 16:56:26.156 INFO 12414 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2018-07-25 16:56:26.156 INFO 12414 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*]
2018-07-25 16:56:26.156 INFO 12414 --- [ost-startStop-1] .s.DelegatingFilterProxyRegistrationBean : Mapping filter: 'springSecurityFilterChain' to: [/*]
2018-07-25 16:56:26.156 INFO 12414 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean : Servlet dispatcherServlet mapped to [/]
2018-07-25 16:56:26.288 INFO 12414 --- [ restartedMain] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting...
2018-07-25 16:56:26.354 INFO 12414 --- [ restartedMain] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed.
2018-07-25 16:56:26.385 INFO 12414 --- [ restartedMain] j.LocalContainerEntityManagerFactoryBean : Building JPA container EntityManagerFactory for persistence unit 'default'
2018-07-25 16:56:26.401 INFO 12414 --- [ restartedMain] o.hibernate.jpa.internal.util.LogHelper : HHH000204: Processing PersistenceUnitInfo [
name: default
...]
2018-07-25 16:56:26.467 INFO 12414 --- [ restartedMain] org.hibernate.Version : HHH000412: Hibernate Core {5.2.16.Final}
2018-07-25 16:56:26.469 INFO 12414 --- [ restartedMain] org.hibernate.cfg.Environment : HHH000206: hibernate.properties not found
2018-07-25 16:56:26.504 INFO 12414 --- [ restartedMain] o.hibernate.annotations.common.Version : HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
2018-07-25 16:56:26.602 INFO 12414 --- [ restartedMain] org.hibernate.dialect.Dialect : HHH000400: Using dialect: org.hibernate.dialect.MySQL5InnoDBDialect
2018-07-25 16:56:27.062 WARN 12414 --- [ restartedMain] o.h.t.s.i.ExceptionHandlerLoggedImpl : GenerationTarget encountered exception accepting command : Error executing DDL via JDBC Statement
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL via JDBC Statement
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlString(SchemaDropperImpl.java:375) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlStrings(SchemaDropperImpl.java:359) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.applyConstraintDropping(SchemaDropperImpl.java:331) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.dropFromMetadata(SchemaDropperImpl.java:230) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.performDrop(SchemaDropperImpl.java:154) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:126) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:112) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:144) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:312) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:460) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:892) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:57) [spring-orm-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) [spring-orm-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:390) [spring-orm-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:377) [spring-orm-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) [spring-orm-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1761) [spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1698) [spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:579) [spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:501) [spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) [spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) [spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) [spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1089) ~[spring-context-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:859) ~[spring-context-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at com.packt.cardatabase.CardatabaseApplication.main(CardatabaseApplication.java:28) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_161]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_161]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_161]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_161]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.0.1.RELEASE.jar:2.0.1.RELEASE]
Caused by: java.sql.SQLSyntaxErrorException: (conn=342) Table 'cardb.car' doesn't exist
at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.get(ExceptionMapper.java:177) ~[mariadb-java-client-2.2.3.jar:na]
at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.getException(ExceptionMapper.java:110) ~[mariadb-java-client-2.2.3.jar:na]
at org.mariadb.jdbc.MariaDbStatement.executeExceptionEpilogue(MariaDbStatement.java:228) ~[mariadb-java-client-2.2.3.jar:na]
at org.mariadb.jdbc.MariaDbStatement.executeInternal(MariaDbStatement.java:334) ~[mariadb-java-client-2.2.3.jar:na]
at org.mariadb.jdbc.MariaDbStatement.execute(MariaDbStatement.java:386) ~[mariadb-java-client-2.2.3.jar:na]
at com.zaxxer.hikari.pool.ProxyStatement.execute(ProxyStatement.java:95) ~[HikariCP-2.7.8.jar:na]
at com.zaxxer.hikari.pool.HikariProxyStatement.execute(HikariProxyStatement.java) ~[HikariCP-2.7.8.jar:na]
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
... 40 common frames omitted
Caused by: java.sql.SQLException: Table 'cardb.car' doesn't exist
Query is: alter table car drop foreign key FK2mqqwvxtowv4vddvtsmvtiqa2
at org.mariadb.jdbc.internal.util.LogQueryTool.exceptionWithQuery(LogQueryTool.java:119) ~[mariadb-java-client-2.2.3.jar:na]
at org.mariadb.jdbc.internal.protocol.AbstractQueryProtocol.executeQuery(AbstractQueryProtocol.java:199) ~[mariadb-java-client-2.2.3.jar:na]
at org.mariadb.jdbc.MariaDbStatement.executeInternal(MariaDbStatement.java:328) ~[mariadb-java-client-2.2.3.jar:na]
... 44 common frames omitted
[ . . . Mapping details here, omitted]
2018-07-25 16:56:27.118 INFO 12414 --- [ restartedMain] o.h.t.schema.internal.SchemaCreatorImpl : HHH000476: Executing import script 'org.hibernate.tool.schema.internal.exec.ScriptSourceInputNonExistentImpl@23352c6f'
2018-07-25 16:56:27.121 INFO 12414 --- [ restartedMain] j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default'
2018-07-25 16:56:28.047 INFO 12414 --- [ restartedMain] o.s.s.web.DefaultSecurityFilterChain : Creating filter chain: org.springframework.security.web.util.matcher.AnyRequestMatcher@1, [org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter@7ec73b7e, org.springframework.security.web.context.SecurityContextPersistenceFilter@6f233313, org.springframework.security.web.header.HeaderWriterFilter@1e641fa3, org.springframework.security.web.csrf.CsrfFilter@7c5a0312, org.springframework.security.web.authentication.logout.LogoutFilter@176619be, org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter@26add7c1, org.springframework.security.web.authentication.ui.DefaultLoginPageGeneratingFilter@4030f929, org.springframework.security.web.authentication.www.BasicAuthenticationFilter@2ea06fad, org.springframework.security.web.savedrequest.RequestCacheAwareFilter@6ce594ae, org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter@6159e3c1, org.springframework.security.web.authentication.AnonymousAuthenticationFilter@51157300, org.springframework.security.web.session.SessionManagementFilter@5be9c504, org.springframework.security.web.access.ExceptionTranslationFilter@4506e3d3, org.springframework.security.web.access.intercept.FilterSecurityInterceptor@1f44843c]
org.springframework.http.HttpEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.ProfileController.listAllFormsOfMetadata()
2018-07-25 16:56:28.632 INFO 12414 --- [ restartedMain] o.s.b.d.a.OptionalLiveReloadServer : LiveReload server is running on port 35729
2018-07-25 16:56:28.668 INFO 12414 --- [ restartedMain] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2018-07-25 16:56:28.670 INFO 12414 --- [ restartedMain] o.s.j.e.a.AnnotationMBeanExporter : Bean with name 'dataSource' has been autodetected for JMX exposure
2018-07-25 16:56:28.676 INFO 12414 --- [ restartedMain] o.s.j.e.a.AnnotationMBeanExporter : Located MBean 'dataSource': registering with JMX server as MBean [com.zaxxer.hikari:name=dataSource,type=HikariDataSource]
2018-07-25 16:56:28.712 INFO 12414 --- [ restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2018-07-25 16:56:28.715 INFO 12414 --- [ restartedMain] c.p.cardatabase.CardatabaseApplication : Started CardatabaseApplication in 4.726 seconds (JVM running for 5.165)
这是我的仓库中的代码： https://github.com/Kallaste/spring_login_server_example_so
答案 0 :(得分：2)
如果您的应用程序仍在运行，我不会担心。 Hibernate在启动时会引发很多“信息性”错误。它只是试图弄清楚要使数据库处于可以运行应用程序的状态，该怎么做。
如果使用create-drop或仅使用create的应用程序运行良好，请尝试仅使用create运行一次，以便生成所有内容，然后将其更改为validate因此，下次只验证您的数据库架构。
在生产环境中，除非您非常确定更改将被正确应用，否则通常不让Hibernate自己更新数据库架构，而是手动应用更改并迁移数据。
答案 1 :(得分：0)
添加如下所示的@Table注释
@Table(name="car")在汽车实体中。总是给表起名字。
注意：
1）当ddl-auto = create-drop时，如果您没有@Table（name =“ car”），则总是会遇到此异常。
2）当ddl-auto = create-drop时，如果您只有第一次拥有@Table（name =“ car”），则将获得此异常。
因此，请尝试将ddl-auto值更改为create-drop以外的值。也许您可以使用“创建”或“更新”
希望这会有所帮助。
答案 2 :(得分：0)
您应该在第一次运行应用程序时使用create，但下次运行时必须使用update。
使用create时，您将创建模式并销毁先前的数据。
并且create-drop在会话结束时销毁架构。 update仅更新您的架构。
答案 3 :(得分：0)
update应该仍然有效。如果表不存在，它将表现为create。
您确定您的数据库和DBDialect匹配吗？
答案 4 :(得分：0)
需要在 application.properties 文件中更改 spring.jpa.hibernate.ddl-auto =update 而不是 create-drop。< br/> 因为它会在应用程序启动时删除数据库，因此它不会找到所需的事件表来更改任何内容。