EJB常用生成数据库注解

@Id                                                                                                                                      主键标识

@GeneratedValue(strategy = GenerationType.AUTO)                                              Id自动增长

@Column(name = "bh", length=25)                                                                             列标识，name为列名， length列的长度

@Temporal(TemporalType.TIMESTAMP)                                                                   日期标识，TemporalType枚举类型，TIMESTAMP为年月日时间，DATE为年月日

@Enumerated(EnumType.STRING)                                                                           枚举类型

@Lob()                                                                                                                               大文件类型

@Basic(fetch = FetchType.EAGER, optional = true)                                                 EAGER立即加载，lazy延迟加载