0与1的世界

1.hibernate注解 声明实体Bean   @Entity public class Flight implements Serializable {   Long id;   @Id   public Long getId() { return id; }   public void setId(Long id) { this.id = id; } }   @En...

不同数据库 自增长ID配置 正对不同的数据库可以同时使用        @Id        @GeneratedValue(strategy = GenerationType.AUTO)2 针对mysql @Id @GeneratedValue(strategy = GenerationType.IDENTITY)3 针对oracle       @Id       @GeneratedV...

On saveAndFlush, changes will be flushed to DB immediately in this command. With save, this is not necessarily true, and might stay just in memory, until flush or commit commands are issued.   But ...