java - Wildfly Greeter 快速入门项目

Question

'greeter' 是 WildFly 8 中的一个快速入门项目，用于作为教程演示基本的 Hibernate 数据库和 JPA 功能。在项目中，我不明白H2数据库中何时以及如何创建“USERS”数据库。这是两个用于数据库创建和设置的相关文件:

1. META-INF/persistence.xml

<persistence version="2.0"
    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">
    <persistence-unit name="primary">
        <!-- If you are running in a production environment, add a managed 
            data source, this example data source is just for development and testing! -->
        <!-- The datasource is deployed as WEB-INF/greeter-quickstart-ds.xml, 
            you can find it in the source at src/main/webapp/WEB-INF/greeter-quickstart-ds.xml -->
        <jta-data-source>java:jboss/datasources/GreeterQuickstartDS</jta-data-source>
        <properties>
            <!-- Properties for Hibernate -->
            <property name="hibernate.hbm2ddl.auto" value="create-drop" />
            <property name="hibernate.show_sql" value="false" />
        </properties>
    </persistence-unit>
</persistence>

WEB-INF/greeter-quickstart-ds.xml

<datasources xmlns="http://www.jboss.org/ironjacamar/schema"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.jboss.org/ironjacamar/schema http://docs.jboss.org/ironjacamar/schema/datasources_1_0.xsd">
    <!-- The datasource is bound into JNDI at this location. We reference 
        this in META-INF/persistence.xml -->
    <datasource jndi-name="java:jboss/datasources/GreeterQuickstartDS"
        pool-name="greeter-quickstart" enabled="true" use-java-context="true">
        <connection-url>jdbc:h2:mem:greeter-quickstart;DB_CLOSE_ON_EXIT=FALSE;DB_CLOSE_DELAY=-1</connection-url>
        <driver>h2</driver>
        <security>
            <user-name>sa</user-name>
            <password>sa</password>
        </security>
    </datasource>
</datasources>

/wildfly-greeter/src/main/resources/import.sql

插入用户(ID、用户名、名字、姓氏)值(-1、'jdoe'、'John'、'Doe')；

插入用户(ID、用户名、名字、姓氏)值(-2、'emuster'、'Erika'、'Mustermann')；

默认情况下，H2数据库系统不自带USERS数据库，该数据库是demo使用的。那么这个演示项目中的“USERS”是如何创建的呢？谢谢。

Answer 1

由于 persistence.xml 中的以下设置，运行项目时会自动创建 USERS 数据库:

<property name="hibernate.hbm2ddl.auto" value="create-drop" />