JPA应用备份

JPA应用备份

一.DATE类型保存为时分秒
@Temporal(TemporalType.TIMESTAMP)
 @Column(name = "UPDATE_TIME", unique = false, nullable = true, insertable = true, updatable = true, length = 7)
取出来展示的时候用toLocalString就行了


二.增加临时字段
@Transient

三.主键table生成
@Id
 @TableGenerator(name="GENERATOR_ID",table="PF_GENERATOR") 
 @GeneratedValue(strategy=GenerationType.TABLE, generator="GENERATOR_ID")
 @Column(name = "ID", unique = true, nullable = false, insertable = true, updatable = true, precision = 10, scale = 0)


create table PF_GENERATOR
(
  SEQUENCE_NAME          VARCHAR2(40) primary key,
  SEQUENCE_NEXT_HI_VALUE NUMBER(10)
)
表也要生成javaBean


四.删除分为两步
StCreditType ct = em.merge(creditType);
 em.remove(ct);

五.操作数据库头部
@Transactional
public class CreditTypeServiceImpl implements CriditTypeService {

 private EntityManager em;

 @PersistenceContext
 public void setEm(EntityManager em) {
  this.em = em;
 }