如何跳过超类表的模式生成？ Java/JPA/休眠/注释/Maven/hbm2ddl

Question

我们的应用程序需要与另一个本地运行的应用程序共享现有的数据库表，因此，我希望引用此表但跳过为其生成 DDL。我还希望将应用程序架构中的表定义为别名或 MySQL 合并表，但我可以将其添加到手动脚本中，该脚本将在生成的架构脚本之前运行。

如何指定从 myapp-schema-ddl.sql 输出中省略 shared_schema 表的 create 和 alter table DDL？

来自 commons/src/main/java/com/company/shared/SharedSuperEntity.java：

@Entity
@Table(name="shared_entity", catalog = "shared_schema")
@Inheritance(strategy = InheritanceType.JOINED)
public class SharedSuperEntity {
    // fields, etc...
}

来自 myapp/src/main/java/com/company/shared/SharedSuperEntity.java：

@Entity
@Table(name="local_entity", catalog = "local_schema")
public class LocalEntity extends SharedSuperEntity {
    // fields, etc...
}

来自 myapp/src/main/resources/META_INF/persistence.xml：

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
version="2.0">
<persistence-unit name="MyAppPU" transaction-type="JTA">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <jta-data-source>java:/LocalDS</jta-data-source>
    <class>com.company.shared.SharedSuperEntity</class>
    <class>com.company.myapp.LocalEntity</class>
    <exclude-unlisted-classes>true</exclude-unlisted-classes>
    <shared-cache-mode>NONE</shared-cache-mode>
    <validation-mode>AUTO</validation-mode>
    <properties>
        <property name="hibernate.transaction.manager_lookup_class" value="org.hibernate.transaction.JBossTransactionManagerLookup" />
        <property name="hibernate.show_sql" value="false" />
        <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect" />
        <property name="hibernate.bytecode.use_reflection_optimizer" value="false" />
        <property name="hibernate.default_batch_fetch_size" value="4" />
        <property name="hibernate.default_entity_mode" value="pojo" />
        <property name="hibernate.generate_statistics" value="false" />
        <property name="hibernate.jdbc.batch_size" value="0" />
        <property name="hibernate.jdbc.batch_versioned_data" value="true" />
        <property name="hibernate.jdbc.fetch_size" value="0" />
        <property name="hibernate.jdbc.use_get_generated_keys" value="false" />
        <property name="hibernate.jdbc.use_scrollable_resultset" value="false" />
        <property name="hibernate.jdbc.use_streams_for_binary" value="false" />
        <property name="hibernate.hibernate.max_fetch_depth" value="3" />
        <property name="hibernate.order_updates" value="true" />
        <property name="hibernate.query.substitutions" value="true 1, false 0, yes 'Y', no 'N'" />
        <property name="hibernate.use_identifer_rollback" value="true" />
        <property name="hibernate.use_outer_join" value="false" />
        <property name="hibernate.use_sql_comments" value="false" />
        <property name="hibernate.id.new_generator_mappings" value="true" />
    </properties>
</persistence-unit>

从 myapp/pom.xml 中：

        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>hibernate3-maven-plugin</artifactId>
            <version>2.2</version>
            <configuration>
                <components>
                    <component>
                        <name>hbm2ddl</name>
                        <implementation>jpaconfiguration</implementation>
                    </component>
                </components>
                <componentProperties>
                    <persistenceunit>MyAppPU</persistenceunit>
                    <outputfilename>myapp-schema-ddl.sql</outputfilename>
                    <drop>false</drop>
                    <create>true</create>
                    <export>false</export>
                    <format>true</format>
                    <jdk5>true</jdk5>
                </componentProperties>
            </configuration>
            <dependencies>
                <dependency>
                    <groupId>org.hibernate</groupId>
                    <artifactId>hibernate-core</artifactId>
                    <version>3.6.0.Final</version>
                    <scope>compile</scope>
                </dependency>
                <dependency>
                    <groupId>org.hibernate</groupId>
                    <artifactId>hibernate-entitymanager</artifactId>
                    <version>3.6.0.Final</version>
                    <scope>compile</scope>
                </dependency>
                <dependency>
                    <groupId>org.hibernate.javax.persistence</groupId>
                    <artifactId>hibernate-jpa-2.0-api</artifactId>
                    <version>1.0.0.Final</version>
                    <scope>compile</scope>
                </dependency>
                <dependency>
                    <groupId>mysql</groupId>
                    <artifactId>mysql-connector-java</artifactId>
                    <version>5.1.16</version>
                    <type>jar</type>
                    <scope>compile</scope>
                </dependency>
            </dependencies>
        </plugin>

Answer 1

我不认为 Hibernate 直接支持这一点。您可以制作两个配置文件：一个列出运行时的所有映射类，另一个省略用于模式生成的违规类。否则，您可能会查看某种后处理，例如 sed 脚本，以便在事后删除 DDL。