使用自定义定界符通过 spring 引导生成 DDL

Question

我想使用 spring 引导 v1.4.3 和 JPA - Hibernate 5.0.11 生成创建和删除 ddl 脚本。

我找到的大多数答案都使用 javax.persistence.schema-generation 属性。例如。

这种方法的问题在于它输出的 sql 语句没有分隔符。例如

create table ... (...)
create table ... (...)

我希望它输出带有分隔符 ;

的语句

create table ... (...);
create table ... (...);

但我找不到任何 javax.persistence.schema-generation 属性来配置它。

所以我想使用SchemaExport from hibernate, because you can set the delimiter property。但是要创建一个 SchemaExport，我需要一个 MetadataImplementor（未弃用 api）。

我不知道如何从 spring 引导中获取 MetadataImplementor。

有谁知道有没有

a javax.persistence.schema-generation 属性定义分隔符
或如何创建 SchemaExport（获取依赖项）
或者有别的解决办法？

这是一些您可以玩的代码

@SpringBootApplication
@ComponentScan(basePackageClasses = Application.class)
@EntityScan(basePackageClasses = User.class)
public class Application {

    @Bean
    public ApplicationRunner getApplicationRunner() {
        return new ApplicationRunner() {

            public void run(ApplicationArguments args) throws Exception {
                // MetadataImplementor metadataImplementor = ???;
                // new SchemaExport(metadataImplementor);
            }
        };
    }

    public static void main(String[] args) {
        SpringApplication application = new SpringApplication(Application.class);
        application.run(args);
    }

}

实体Class

@Entity
public class User {

    @Id
    @GeneratedValue
    private Long id;
    
    private String name;
    
    public Long getId() {
        return id;
    }
    
    public String getName() {
        return name;
    }
    
    public void setName(String name) {
        this.name = name;
    }
    
}

另一个实体class

@Entity
public class Person {

    @Id
    @GeneratedValue
    private Long id;
    
    private String name;
    
    public Long getId() {
        return id;
    }
    
    public String getName() {
        return name;
    }
    
    public void setName(String name) {
        this.name = name;
    }
    
}

application.properties

spring.jpa.properties.javax.persistence.schema-generation.create-source=metadata
spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=create.sql

maven 依赖项

<properties>
    <spring.boot.version>1.4.3.RELEASE</spring.boot.version>
</properties>

<dependencyManagement>
    <dependencies>
        <dependency>
            <!-- Import dependency management from Spring Boot -->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-dependencies</artifactId>
            <version>${spring.boot.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
    </dependency>
</dependencies>

使用 Hibernate 5.0

我刚刚在休眠模式下尝试了上面的代码 5.0.11.Final。您唯一必须改变的是

SchemaExport schemaExport = new SchemaExport((MetadataImplementor) metadata);
schemaExport.setDelimiter(";");
schemaExport.setFormat(false);
schemaExport.setOutputFile(dropAndCreateDdlFile.getAbsolutePath());

schemaExport.execute(true, false, false, false);

或者当然让 java 配置 return 一个 MetadataImplementor 而不是 Metadata 并更改 ApplicationRunner 构造函数参数。

Answer 1

我发现 sessionFactory 包含 schemaExport 值，例如 createSQL, dropSQL, outputFile 和 delimiter。

sessionFactory 作为 Bean 可以这样创建，然后可用于自动装配：

....

@Autowired
private EntityManagerFactory entityManagerFactory;

@Bean
public SessionFactory sessionFactory() {
    if (entityManagerFactory.unwrap(SessionFactory.class) == null) {
        throw new NullPointerException("factory is not a hibernate factory");
    }
    return entityManagerFactory.unwrap(SessionFactory.class);
}

这不是可行的解决方案，但可以帮助您使用 sessionFactory 手动配置 schemaExport。我找不到仅使用属性并在那里设置分隔符的解决方案。但可能会成为寻找工作解决方案的小帮手。

如果我找到更多有用的信息，我会更新我的答案。

Answer 2

经过大量调查，我认为我终于找到了一个使用 public API 的简单解决方案。我找到的解决方案使用休眠5.2（更具体5.2.6.Final）。不过我觉得也可以适配5.0

这是我的springjava配置

@Configuration
@AutoConfigureAfter({ HibernateJpaAutoConfiguration.class })
public class HibernateJavaConfig {

    @ConditionalOnMissingBean({ Metadata.class })
    @Bean
    public Metadata getMetadata(StandardServiceRegistry standardServiceRegistry,
            PersistenceUnitInfo persistenceUnitInfo) {
        MetadataSources metadataSources = new MetadataSources(standardServiceRegistry);

        List<String> managedClassNames = persistenceUnitInfo.getManagedClassNames();
        for (String managedClassName : managedClassNames) {
            metadataSources.addAnnotatedClassName(managedClassName);
        }

        Metadata metadata = metadataSources.buildMetadata();
        return metadata;
    }

    @ConditionalOnMissingBean({ StandardServiceRegistry.class })
    @Bean
    public StandardServiceRegistry getStandardServiceRegistry(JpaProperties jpaProperties) {
        StandardServiceRegistryBuilder ssrb = new StandardServiceRegistryBuilder();

        Map<String, String> properties = jpaProperties.getProperties();
        ssrb.applySettings(properties);

        StandardServiceRegistry ssr = ssrb.build();
        return ssr;
    }

    @ConditionalOnMissingBean({ PersistenceUnitInfo.class })
    @Bean
    public PersistenceUnitInfo getPersistenceUnitInfo(EntityScanPackages entityScanPackages) {
        List<String> packagesToScan = entityScanPackages.getPackageNames();

        DefaultPersistenceUnitManager persistenceUnitManager = new DefaultPersistenceUnitManager();

        String[] packagesToScanArr = (String[]) packagesToScan.toArray(new String[packagesToScan.size()]);
        persistenceUnitManager.setPackagesToScan(packagesToScanArr);
        persistenceUnitManager.afterPropertiesSet();

        PersistenceUnitInfo persistenceUnitInfo = persistenceUnitManager.obtainDefaultPersistenceUnitInfo();
        return persistenceUnitInfo;
    }

}

java 配置创建了一个 Metadata bean。这个 bean 可以在 hibernate 5.2 中用于执行模式生成。例如

@Component
public class GenerateDDLApplicationRunner implements ApplicationRunner {

    private Metadata metadata;

    public GenerateDDLApplicationRunner(Metadata metadata) {
        this.metadata = metadata;
    }

    public void run(ApplicationArguments args) throws Exception {
        File dropAndCreateDdlFile = new File("drop-and-create.ddl");
        deleteFileIfExists(dropAndCreateDdlFile);

        SchemaExport schemaExport = new SchemaExport();
        schemaExport.setDelimiter(";");
        schemaExport.setFormat(false);
        schemaExport.setOutputFile(dropAndCreateDdlFile.getAbsolutePath());

        schemaExport.execute(EnumSet.of(TargetType.SCRIPT), Action.BOTH, metadata);
    }

    private void deleteFileIfExists(File dropAndCreateDdlFile) {
        if (dropAndCreateDdlFile.exists()) {
            if (!dropAndCreateDdlFile.isFile()) {
                String msg = MessageFormat.format("File is not a normal file {0}", dropAndCreateDdlFile);
                throw new IllegalStateException(msg);
            }

            if (!dropAndCreateDdlFile.delete()) {
                String msg = MessageFormat.format("Unable to delete file {0}", dropAndCreateDdlFile);
                throw new IllegalStateException(msg);
            }
        }
    }

}

休眠方言是使用 spring 引导 application.properties 配置的。就我而言：

spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL57InnoDBDialect

Answer 3

这可能是一种解决方法，但就我而言，在项目构建期间添加分号就足够了。您可以使用 Maven 插件来做到这一点，例如：

<plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>1.6.0</version>
                <executions>
                    <execution>
                        <id>add-semicolon-to-sql-file</id>
                        <phase>generate-resources</phase>
                        <goals>
                            <goal>exec</goal>
                        </goals>
                        <configuration>
                            <executable>sed</executable>
                            <arguments>
                                <argument>-i</argument>
                                <argument>/;$/!s/$/;/</argument>
                                <argument>src/main/resources/db/migration/V1__init.sql</argument>
                            </arguments>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

Answer 4

我修改了 René 的解决方案以在 Spring Boot 2 中工作。测试版本 2.0.4:

@Configuration
@AutoConfigureAfter({ HibernateJpaAutoConfiguration.class })
public class HibernateMetadataBean {

    @ConditionalOnMissingBean({ Metadata.class })
    @Bean
    public Metadata getMetadata(StandardServiceRegistry standardServiceRegistry,
                                PersistenceUnitInfo persistenceUnitInfo) {
        MetadataSources metadataSources = new MetadataSources(standardServiceRegistry);

        List<String> managedClassNames = persistenceUnitInfo.getManagedClassNames();
        for (String managedClassName : managedClassNames) {
            metadataSources.addAnnotatedClassName(managedClassName);
        }

        return metadataSources.buildMetadata();
    }

    @ConditionalOnMissingBean({ StandardServiceRegistry.class })
    @Bean
    public StandardServiceRegistry getStandardServiceRegistry(JpaProperties jpaProperties) {
        StandardServiceRegistryBuilder ssrb = new StandardServiceRegistryBuilder();

        Map<String, String> properties = jpaProperties.getProperties();
        ssrb.applySettings(properties);

        return ssrb.build();
    }

    @ConditionalOnMissingBean({ PersistenceUnitInfo.class })
    @Bean
    public PersistenceUnitInfo getPersistenceUnitInfo(BeanFactory beanFactory) {
        List<String> packagesToScan = EntityScanPackages.get(beanFactory).getPackageNames();
        if (packagesToScan.isEmpty() && AutoConfigurationPackages.has(beanFactory)) {
            packagesToScan = AutoConfigurationPackages.get(beanFactory);
        }

        DefaultPersistenceUnitManager persistenceUnitManager = new DefaultPersistenceUnitManager();

        String[] packagesToScanArr = StringUtils.toStringArray(packagesToScan);
        persistenceUnitManager.setPackagesToScan(packagesToScanArr);
        persistenceUnitManager.afterPropertiesSet();

        return persistenceUnitManager.obtainDefaultPersistenceUnitInfo();
    }

}

Answer 5

您可能想尝试设置以下 Hibernate 属性：

spring.jpa.properties.hibernate.hbm2ddl.delimiter=;

#in addition to the other standard JPA properties you refered to, namely:
spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=create.sql

我发现这是在 Spring Boot 2.1.2.RELEASE + 匹配的 Hibernate 版本 (5.3.7.Final) 我需要相同功能的项目。

它可能非常适合您的 Hibernate 环境。

有点偏离主题，但我仍然有一个问题：Hibernate 附加到create.sql。我希望我找到了一种方法来替换文件内容。

使用自定义定界符通过 spring 引导生成 DDL

Generate DDL with spring boot using a custom delimiter

ddl

spring

hibernate

spring-data-jpa

spring-boot

实体Class

另一个实体class

application.properties

maven 依赖项