Hibernate中ID生成策略 - 数据库编程

public static void afterClass(){ sf.close(); } }

（3）验证

select * from _teacher;



desc _teacher;

数据插入成功，id为int(11)，主键，auto_increment

在使用Annotation的时候，除了使用auto策略，还可以使用increment,identity,sequence,table等等。

小实验2：

（1）修改Teacher.java.修改策略为identity

package com.zgy.hibernate.model;



import java.util.Date;



import javax.annotation.Generated;

import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.EnumType;

import javax.persistence.Enumerated;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

import javax.persistence.Table;

import javax.persistence.Temporal;

import javax.persistence.TemporalType;

import javax.persistence.Transient;



@Entity

@Table(name="_teacher")

public class Teacher {

private int id;

private String name;

private String title;

private String address;

private String wifeName;

private Date birth;

private ZhiCheng zhiCheng;

@Id

@GeneratedValue(strategy=GenerationType.IDENTITY)

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

@Column(name="_name")

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getTitle() {

return title;

}

public void setTitle(String title) {

this.title = title;

}

public String getAddress() {

return address;

}

public void setAddress(String address) {

this.address = address;

}



public String getWifeName() {

return wifeName;

}

public void setWifeName(String wifeName) {

this.wifeName = wifeName;

}

@Temporal(TemporalType.DATE)

public Date getBirth() {

return birth;

}

public void setBirth(Date birth) {

this.birth = birth;

}

@Enumerated(EnumType.STRING)

public ZhiCheng getZhiCheng() {

return zhiCheng;

}

public void setZhiCheng(ZhiCheng zhiCheng) {

this.zhiCheng = zhiCheng;

}





}

（2）测试

（3）验证

select * from _teacher;

desc _teacher;

使用table策略：

@javax.persistence.TableGenerator(

name="Teacher_GEN",

table="GENERATOR_TABLE",

pkColumnName="pkkey",

valueColumnName="pkvalue",

pkColumnValue="Teacher",

allocationSize=1

)

以上Annotation的意义：首先是定义了一个generator,该generator的名字叫做Teacher_GEN,生成一张表，表名为GENERATOR_TABLE，该表有两个字段，分别为pkColumnName和valueColumnName。这个表的第一条数据是：Teacher ， 1。其下一条数据的步长值，即Teacher表的下一条数据的值会是2

小实验3：

（1）修改Teacher.java类

package com.zgy.hibernate.model;



import java.util.Date;



import javax.annotation.Generated;

import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.EnumType;

import javax.persistence.Enumerated;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

import javax.persistence.Table;

import javax.persistence.Temporal;

import javax.persistence.TemporalType;

import javax.persistence.Transient;



@Entity

@javax.persistence.TableG

Hibernate中ID生成策略(四)