Java Spring Boot HIbernate 问题：使用 ddl-auto=create-drop 通过 JDBC 语句执行 DDL 时出错

Spring Boot HIbernate Issue: Error executing DDL via JDBC Statement with ddl-auto=create-drop

提问by Kallaste

I am a novice with Spring and Hibernate and have tried everything I could find to fix this with no luck. Any assistance would be greatly appreciated. I am currently following a sample project in a book, and am getting an error that says "GenerationTarget encountered exception accepting command : Error executing DDL via JDBC Statement." I am using a MariaDB database, and my hibernate dialect is org.hibernate.dialect.MySQL5InnoDBDialect.

我是 Spring 和 Hibernate 的新手，我已经尝试了所有我能找到的方法来解决这个问题，但没有运气。任何帮助将不胜感激。我目前正在关注一本书中的一个示例项目，并且收到一条错误消息，指出“GenerationTarget 遇到异常接受命令：通过 JDBC 语句执行 DDL 时出错”。我正在使用 MariaDB 数据库，我的休眠方言是 org.hibernate.dialect.MySQL5InnoDBDialect。

The query causing this issue is

导致此问题的查询是

alter table car drop foreign key FK2mqqwvxtowv4vddvtsmvtiqa2;

If I try to run this query directly in the database it works fine. I have the ddl-auto property set to create-drop, so maybe it is trying to execute this query when the car table has been dropped and is not there? I'm not sure why it would do that or how to turn off this behavior if that is the problem.

如果我尝试直接在数据库中运行此查询，它工作正常。我将 ddl-auto 属性设置为 create-drop，所以当 car 表被删除并且不在那里时，它可能正在尝试执行此查询？我不确定为什么会这样做，或者如果这是问题，如何关闭这种行为。

If I change ddl-auto to validate or update, the application fails to run at all. If I change it to create, it works fine and I get no errors.

如果我将 ddl-auto 更改为验证或更新，则应用程序根本无法运行。如果我将其更改为创建，则它可以正常工作并且不会出现任何错误。

With create-drop, the application does connect to the database and all my tables are created. The tables are still defined as they should be, but the error remains.

使用 create-drop，应用程序确实连接到数据库并创建了我的所有表。表格仍按原样定义，但错误仍然存​​在。

Console output:

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##代码##(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)

Here is the code on my repo: https://github.com/Kallaste/spring_login_server_example_so

这是我的 repo 上的代码：https: //github.com/Kallaste/spring_login_server_example_so

回答by Kathirvel Subramanian

Add @Table annotation like below

添加@Table注释，如下所示

@Table(name="car")in car entity. Always give name to table .

@Table(name="car")在汽车实体。总是给 table 命名。

Note:

笔记：

1) When ddl-auto=create-drop and if you don't have @Table(name="car") always you will get this exception.

1) 当 ddl-auto=create-drop 并且如果你没有 @Table(name="car") 总是你会得到这个例外。

2) When ddl-auto=create-drop and if you have @Table(name="car") the first time alone you will get this exception.

2) 当 ddl-auto=create-drop 并且如果你第一次有 @Table(name="car") 你会得到这个异常。

So try to change the ddl-auto value to other than create-drop . May be you can use "create" or "update"

因此，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”

Hope this helps.

希望这可以帮助。

回答by Sebastiaan van den Broek

I wouldn't worry about it if your application still runs. Hibernate throws a lot of ‘informative' errors on startup. It just tries to figure out what it has to do to get the database in a state where your application can run.

如果您的应用程序仍在运行，我不会担心。Hibernate 在启动时会抛出很多“信息性”错误。它只是试图弄清楚它必须做什么才能使数据库处于您的应用程序可以运行的状态。

If the app runs fine if you use create-dropor just create, then try running it with createjust once so everything is generated and then change it to validateso the next time it only validates your database schema.

如果应用程序运行良好，如果您使用create-drop或create，则尝试只运行create一次，以便生成所有内容，然后将其更改为，validate以便下次仅验证您的数据库架构。

In a production environment you would generally not let Hibernate update the database schema by itself but manually apply changes and migrate data anyway, unless you're very sure the changes would be applied correctly.

在生产环境中，您通常不会让 Hibernate 自行更新数据库架构，而是手动应用更改并迁移数据，除非您非常确定更改将被正确应用。

回答by Gerry Larios

You should use createthe first time you run your application, but the next runs have to have update.

您应该create在第一次运行应用程序时使用，但下次运行时必须使用update.

When you use createyou create the schema and destroy the previous data. And create-dropdestroy the schema in the end of the session. updateonly update you schema.

当您使用时，您将create创建架构并销毁以前的数据。并create-drop在会话结束时销毁模式。update只更新你的架构。

回答by a.khaled

updateshould still be valid. If tables don't exist, it will behave as create.

update应该还是有效的。如果表不存在，它将表现为创建。

Are you sure your DB and DBDialect match?

你确定你的 DB 和 DBDialect 匹配吗？