轉：
http://www.aygfsteel.com/gkm422/archive/2007/11/21/162214.html
注意import javax.xx.Entity ，而不是org.hibernate.xx.Entity。
Descn屬性不存在于數據庫中，用@Transient 注明
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1,需要: Hibernate庫文件,Hibernate Annotations庫,ejb3-persstence.jar(Java 持久化API)
sessionFactory=new AnnotationConfiguration().buildSessionFactory();
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2,<bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<property name="annotatedClasses">
<list>
<value>com.onjava.modelplanes.domain.PlaneType</value>
</list>
</property>
</bean>
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1,@Entity
@Table(name = "teacher_info")
@IdClass(UUIDHexGenerator.class)
public class UserMember implements java.io.Serializable
2,@entity通過getters/setters方法訪問，或直接訪問他的成員變量。
@Entity(access = AccessType.PROPERTY)
@Entity(access = AccessType.FIELD)
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映射標識符
1,@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private String id;
2,@Id(generate=GeneratorType.SEQUENCE, generator='SEQ_STORE')
3,@Id(generate=GeneratorType.IDENTITY)
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映射屬性
1,@Transient
2,@Column(name="PLANE_ID", length=80, nullable=true)
3,@Basic(fetch = FetchType.LAZY)
4,@Serialized 凡標識@Serialized的屬性將被序列化
public Country getCountry() { ... }
5,@Lob標識了存儲對象可能是個CLOB或者BLOB。
@Lob(type=LobType.CLOB)
public String getFullText(){return fullText;}
@Lob(type = LobType.BLOB)
public byte[] getFullCode() {return fullCode;}
@Version 定義樂觀鎖機制使用
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關聯關系:
一、一對一:
1,@OneToOne(mappedBy = "address")
public User getUser() {
return user;
}
1、兩邊都定義了@OneToOne，但都沒有定義mappedBy,則user和address表都會生成到對方的外鍵，雙方都是這個關系的擁有者。
2、兩邊都定義了@OneToOne，如果user定義了mappedBy，則在address表生成到user的外鍵，address是這個關系的擁有者；如果address定義
了mappedBy，則在user表生成到address的外鍵，user是這個關系的擁有者。
二、一對多,多對一:
2,@ManyToOne( cascade = {CascadeType.PERSIST, CascadeType.MERGE} )
3,@OneToMany(mappedBy="planeType",cascade=CascadeType.ALL, fetch=FetchType.EAGER)
@OrderBy("name")
public List<ModelPlane> getModelPlanes() {
return modelPlanes;
}
其中定義mappedBy的是@OneToMany,也就是說One這一方是關系的擁有者。Many一方的表中生成到關聯類的外鍵。
三、@ManyToMany
private Set authors = new HashSet<Author>();
@ManyToMany
public Set<Author> getAuthors(){
return authors;
}
private Set books = new HashSet<Book>();
@ManyToMany(mappedBy="authors")
public Set<Book> getBooks(){
return books;
}
@ManyToMany會生成中間表，具體表名和字段可以通過@AssociationTable來定義，默認的就可以了，同樣關系的非擁有者，需要定義mappedBy屬性。
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命名查詢
你也可以通過注解,利用@NameQueries和@NameQuery注解,如下:
@NamedQueries(
{
@NamedQuery(name="planeType.findAll",query="select p from PlaneType p" ),
@NamedQuery(name="planeType.delete",query="delete from PlaneType where id=:id" )
}
)
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內嵌對象（組件）
@Embedded({
@AttributeOverride(name='iso2', column = @Column(name='bornIso2') ),
@AttributeOverride(name='name', column = @Column(name='bornCountryName') )
})
Country bornIn;
...
}
@Embeddable(access = AccessType.FIELD)
public class Address implements Serializable {
String city;
Country nationality;
}
@Embeddable
public class Country implements Serializable {
private String iso2;
private String name;
public String getIso2() { return iso2; }
public void setIso2(String iso2) { this.iso2 = iso2; }
@Column(name='countryName')
public String getName() { return name; }
public void setName(String name) { this.name = name; }
...
}
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自定義的主鍵生成策略
@javax.persistence.GeneratedIdTable(
name='GEN_TABLE',
table = @Table(name='GENERATOR_TABLE'),
pkColumnName = 'key',
valueColumnName = 'hi'
)
@javax.persistence.TableGenerator(
name='EMP_GEN',
tableName='GEN_TABLE',
pkColumnValue='EMP',
allocationSize=20
)
@javax.persistence.SequenceGenerator(
name='SEQ_GEN',
sequenceName='my_sequence'
)
package org.hibernate.test.metadata;