Spring MVC多实体数据库持久性 [英] Spring mvc multiple entities database persistance

问题描述

Spring MVC中的使用多个数据库"问题-休眠JPA

I'm having troubles with "working with multiple databases" in Spring MVC - hibernate JPA

我有两个名为 user_db 和 portal_db 的数据库.我需要在不同的jpa单元中与他们合作.

I have two databases called user_db and portal_db. I need to work with them in different jpa units.

这是我的 persistance.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_1_0.xsd" version="1.0">

    <persistence-unit name="user_unit" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <class>Package.Entity1</class>

        <properties>
            <property name="hibernate.connection.url" value="jdbc:postgresql://localhost/user_db" />
            <property name="hibernate.connection.useUnicode" value="true" />
            <property name="hibernate.connection.characterEncoding" value="UTF-8" />
            <property name="hibernate.connection.driver_class" value="org.postgresql.Driver" />
            <property name="hibernate.connection.username" value="postgres" />
            <property name="hibernate.connection.password" value="" />
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQL82Dialect" />
            <!--<property name="hibernate.hbm2ddl.auto" value="create-drop" />-->
            <property name="hibernate.hbm2ddl.auto" value="validate" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="true" />
        </properties>
    </persistence-unit>

    <persistence-unit name="portal_unit" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <class>Package.Entity2</class>

        <properties>
            <property name="hibernate.connection.url" value="jdbc:postgresql://localhost/portal_db" />
            <property name="hibernate.connection.useUnicode" value="true" />
            <property name="hibernate.connection.characterEncoding" value="UTF-8" />
            <property name="hibernate.connection.driver_class" value="org.postgresql.Driver" />
            <property name="hibernate.connection.username" value="postgres" />
            <property name="hibernate.connection.password" value="" />
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQL82Dialect" />
            <!--<property name="hibernate.hbm2ddl.auto" value="create-drop"/>-->
            <property name="hibernate.hbm2ddl.auto" value="validate"/>
            <property name="hibernate.show_sql" value="true"/>
            <property name="hibernate.format_sql" value="true"/>
        </properties>
    </persistence-unit>
</persistence>

问题是当我使用create-drop并运行我的项目时，它在两个数据库中都创建了两个实体.像应该仅由user_unit中的Package.Entity1创建的表一样，也是在portal_unit中创建的表.

Problem is When I use create-drop and run my project, it creates both of my entites in both databases. Like table that should be only created by Package.Entity1 in user_unit, is also created in portal_unit.

当我选择，插入，更新我的实体时，我在每个单独的DAO中都设置了持久性单元.

And when I select,insert,update my entites, I set persistance unit in each of my individual DAO's.

例如，在Entity Dao的实现中，我有:

for example, in Entity Dao's implementation I have:

EntityManagerFactory emf = Persistence.createEntityManagerFactory(persistenceUnit);

其中的 persistenceUnit 可以是user_unit或portal_unit，具体取决于实现方式.

where persistenceUnit could be user_unit or portal_unit depending on implementation.

我应该进行哪些更改，以使其不会在两个数据库中创建相同的表?

What changes should I make so it wont create same table in both databases?

推荐答案

在两个持久性单元中都添加<exclude-unlisted-classes>true</exclude-unlisted-classes>或使用JPA 2.x

Add <exclude-unlisted-classes>true</exclude-unlisted-classes> in both of yours persistence units OR use JPA 2.x

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