-- Name属性用于定义持久化单元的名字 (name必选,空值也合法) --> <persistence-unit name="foshanshop"> <! schema创建DDL语句 --> <property name="hibernate.hbm2ddl.auto" value="create-drop"/> </properties> </persistence-unit > </persistence> persistence-unit: 节点可以有一个或多个,每个persistence-unit 节点定义了持久化内容名称、使用的数据源以及持久化产品的专有属性 扩展(persistence-unit) 持久化单元包含的属性有: 在该持久化单元范围(作用域)内的实体类 为实体类提供持久化的持久化提供者(Persistence Provider)或库 实体类的数据源
unitName属性是指定持久化单元的名字,其值是在持久化单元定义文件中persistence-unit标签中的name属性的值。 http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"> <persistence-unit properties> <property name="toplink.ddl-generation" value="create-tables"/> </properties> </persistence-unit
添加多数据源支持 你可以在项目中可以轻松的引用多个数据源 第一步:在persiste.xml中定义多个数据源 <persistence-unit name="default"> javax.persistence.jdbc.url" value="jdbc:mysql://127.0.0.1:3306/test"/> </properties> </persistence-unit > <persistence-unit name="pg"> <provider>org.hibernate.reactive.provider.ReactivePersistenceProvider " value="jdbc:postgresql://localhost/postgres"/> </properties> </persistence-unit
xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"> <persistence-unit /> <property name="hibernate.max_fetch_depth" value="3"/> </properties> </persistence-unit java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd" version="2.0"> <persistence-unit name="myunit" > <provider>org.hibernate.ejb.HibernatePersistence</provider> //Others properties </persistence-unit
4 xsi:schemaLocation="http://java.sun.com/xml/ns/persistence persistence_1_0.xsd "> 5 6 <persistence-unit <property name="hibernate.connection.password" value="root" /> 18 </properties> 19 </persistence-unit
SessionFactory private static EntityManagerFactory em; // 使用静态代码块赋值 static { // 注意:该方法参数必须和persistence.xml中persistence-unit
配置如下内容: <persistence-unit name="ejb_entitybean"> <jta-data-source>java:/MySqlDS</jta-data-source > <property name="hibernate.hbm2ddl.auto" value="update" /> </properties> </persistence-unit
/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd" version="2.1"> <persistence-unit property> <property name="hibernate.connection.password" value="root"></property> </properties> </persistence-unit -- persistence-unit:这个叫做持久化的单元 这个的作用就是配置 访问数据库的信息 name:逻辑意义上可以随便写 但是一般情况下见名之意 这个一般情况下写 举例:就是能够对某几行代码进行事务的管理 --> <persistence-unit property> <property name="hibernate.connection.password" value="root"></property> </properties> </persistence-unit
http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd" version="2.1"> <persistence-unit property name="hibernate.hbm2ddl.auto" value="create"/> </properties> </persistence-unit
> <persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0"> <persistence-unit name value="true"/> <property name="hbm2ddl.auto" value="update"/> </properties> </persistence-unit <tx:annotation-driven transaction-manager="transactionManager"/> </beans> 下面,填充persistence.xml,将persistence-unit > <persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0"> <persistence-unit name property name="connection.is-connection-validation-required" value="true"/> </properties> </persistence-unit
> <persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0"> <persistence-unit name value="true"/> <property name="hbm2ddl.auto" value="update"/> </properties> </persistence-unit <tx:annotation-driven transaction-manager="transactionManager"/> </beans> 下面,填充persistence.xml,将persistence-unit > <persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0"> <persistence-unit name property name="connection.is-connection-validation-required" value="true"/> </properties> </persistence-unit
--配置持久化单元 name:持久化单元名称 transaction-type:事务类型 RESOURCE_LOCAL:本地事务管理 JTA:分布式事务管理 --> <persistence-unit hibernate.format_sql" value="true" /> <property name="hibernate.hbm2ddl.auto" value="create" /> </properties> </persistence-unit
--需要配置persistence-unit节点 持久化单元: name:持久化单元名称 transaction-type:事务管理方式 JTA: 分布式事务管理 RESOURCE_LOCAL: 本地事务管理 --> <persistence-unit name="myJpa" transaction-type <property name="hibernate.hbm2ddl.auto" value="update"/> </properties> </persistence-unit EntityManagerFactory myJpa = Persistence.createEntityManagerFactory("myJpa"); 根据持久化单元名称创建实体管理器工厂,持久化单元名称就是配置文件中 persistence-unit
-- 需要配置一个persistence-unit节点 持久化单元: name 持久化单元名称 transaction-type 事务管理的方式 : Jpa 分布式事务管理 (不同的表存在不同的数据库中) RESOURCE_LOCAL 本地事务管理 (表都存在一个数据库中) --> <persistence-unit /> <property name="hibernate.hbm2ddl.auto" value="update"/> </properties> </persistence-unit
java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"> <persistence-unit name="persistence-unit" transaction-type="RESOURCE_LOCAL"> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl <property name="openjpa.RuntimeUnenhancedClasses" value="supported" /> </properties> </persistence-unit
4 http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd" 5 version="2.0"> 6 7 <persistence-unit <property name="hibernate.hbm2ddl.auto" value="update" /> 22 </properties> 23 </persistence-unit
classes/META-INF这里才能生效 --><persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0"> <persistence-unit hibernate.use_sql_comments" value="false" /> <property name="hibernate.hbm2ddl.auto" value="update" /> </properties> </persistence-unit
User.class, 1); return user.getPassword(); } } 其中PersistenceContext中的unitName一定要跟persistence.xml中的persistence-unit
java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"> <persistence-unit name="persistence-unit" transaction-type="RESOURCE_LOCAL"> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl <property name="openjpa.RuntimeUnenhancedClasses" value="supported" /> </properties> </persistence-unit
xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"> <persistence-unit <property name="hibernate.cache.use_query_cache" value="true"/> </properties> </persistence-unit