我将JPA与hibernate实现一起使用。 我的项目看起来像这样:
我的pom.xml中的依赖
<dependencies>
<!-- JUNIT -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<!-- MYSQL CONNECTOR -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.9</version>
</dependency>
<!-- HIBERNATE -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>4.1.6.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>4.1.6.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-annotations</artifactId>
<version>3.5.5-Final</version>
</dependency>
<dependency>
<groupId>org.hibernate.common</groupId>
<artifactId>hibernate-commons-annotations</artifactId>
<version>4.0.4.Final</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.7</version>
</dependency>
</dependencies>
persistence.xml
<persistence-unit name="manager" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>ma.mahmoud.jpa.Person</class>
<properties>
<property name="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.ImprovedNamingStrategy" />
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLInnoDBDialect" />
<property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/testjpa" />
<property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver" />
<property name="hibernate.connection.username" value="root" />
<property name="hibernate.connection.password" value="root" />
<property name="hibernate.hbm2ddl.auto" value="create-drop" />
<property name="hibernate.connection.charSet" value="UTF-8" />
<property name="hibernate.id.new_generator_mappings" value="false" />
<property name="hibernate.show_sql" value="true" />
</properties>
</persistence-unit>
问题是当我运行main方法时出现此错误:
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'testjpa.person' doesn't exist
我知道数据库中不存在该表,但是当我运行应用程序时,我希望在数据库中创建该表。
主要方法:
public static void main(String[] argv) {
EntityManagerFactory emf = Persistence.createEntityManagerFactory("manager");
EntityManager em = emf.createEntityManager();
EntityTransaction transac = em.getTransaction();
transac.begin();
em.persist(new Person("mahmoud", "lotfi", "morroco"));
transac.commit();
em.close();
emf.close();
}
实体人:
@Entity
@Table(name =“Person”) public class Person实现Serializable {
private static final long serialVersionUID = 4717398914745522714L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;
@Column(name = "last_name", length = 50, nullable = false, unique = false, updatable = true)
private String lastname;
@Column(name = "first_name", length = 50, nullable = false, unique = false, updatable = true)
private String firstname;
@Column(name = "country", length = 50, nullable = true, unique = false, updatable = true)
private String country;
public Person(String lastname, String firstname, String country) {
super();
this.lastname = lastname;
this.firstname = firstname;
this.country = country;
}
public Person() {
}
// GETTERS AND SETTERS ....
答案 0 :(得分:3)
解决方案摘要。
要让Hibernate
在persistence.xml
初始化期间创建表格,必须定义属性hibernate.hbm2ddl.auto
。 (见:https://docs.jboss.org/hibernate/orm/4.1/manual/en-US/html/ch03.html#configuration-transaction-properties)
<property name="hibernate.hbm2ddl.auto" value="create-drop" />
对于MySQL&gt; = 5.x数据库,如果属性hibernate.dialect
设置为
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLInnoDBDialect"
该属性必须设置为
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect"
获取的信息