JPA中常用的主键生成策略

JPA中常用的主键生成策略

@TableGenerator(name  =   " id_generator " ,  // 生成器的名称,与generator值对应
                table = " id_generator " ,  // 记录主键的表
                allocationSize = 1 ,    // 每次加一
                pkColumnName = " gen_name " ,     //  表用于标识区分主键 
                valueColumnName = " gen_value " ,  // 主键的值
                pkColumnValue = " t_role_id "    //  gen_name 的值
                )

@Id
@GeneratedValue(strategy = GenerationType.TABLE,generator = " id_generator")

 
  @Id
    @SequenceGenerator(name = " role_sequence " ,sequenceName = " seq_t_role " )
    @GeneratedValue(strategy = GenerationType.SEQUENCE,generator = " role_sequence " )

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)