JPA 一对多排序示例.pdfVIP

JPA ⼀对多排序⽰例 JPA教程 - JPA⼀对多排序⽰例 以下代码显⽰如何在⼀对多映射中按属性设置顺序。 @OrderBy(“name ASC)设置按⼈员名称设置的⼈员排序。 @OneToMany(targetEntity=Person.class mappedBy=department) @OrderBy(name ASC) private SetPerson persons = new HashSetPerson(); 例⼦ 下⾯的代码来 PersonDaoImpl .j ava 。 package mon; import java.util.List; import javax .persistence.EntityManager; import javax .persistence.PersistenceContext; import javax .persistence.Query; import org.springframework.transaction.annotation.Transactional; @Transactional public class PersonDaoImpl { public void test(){ Department d = new Department(); d.setName(Design); Person p1 = new Person(Tom); p1.setDepartment(d); Person p2 = new Person(Jack); p2.setDepartment(d); d.getPersons().add(p1); d.getPersons().add(p2); em.persist(p1); em.persist(p2); em.persist(d); } @PersistenceContext private EntityManager em; } 下⾯的代码来 Department .j ava 。 package mon; import java.util.HashSet; import java.util.Set; import javax .persistence.Entity; import javax .persistence.GeneratedValue; import javax .persistence.GenerationType; import javax .persistence.Id; import javax .persistence.OneToMany; import javax .persistence.OrderBy; @Entity public class Department { @Id @GeneratedValue(strategy=GenerationType.IDENTITY) private long id; private String name; @OneToMany(targetEntity=Person.class mappedBy=department) @OrderBy(name ASC) private SetPerson persons = new HashSetPerson(); public SetPerson getPersons() { return persons; } public void setPersons(SetPerson persons) { this.persons = persons; } public long getId() { return id; } public void setId(long id) { this.id = id; } public String getName() { return name; } public void setName(String name) { = name; } @Override public String toString() { return Department [id= + id + name=