一、用到的实体类如下:
Student.java
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package com.company.entity;
import java.io.Serializable;
import java.util.Date;
public class Student implements Serializable{
private static final long serialVersionUID = 1L;
private int id;
private String name;
private Date birth;
private Group group;
public Group getGroup() {
return group;
}
public void setGroup(Group group) {
this .group = group;
}
public int getId() {
return id;
}
public void setId( int id) {
this .id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this .name = name;
}
public Date getBirth() {
return birth;
}
public void setBirth(Date birth) {
this .birth = birth;
}
@Override
public String toString() {
return "Student [birth=" + birth + ", group=" + group + ", id=" + id
+ ", name=" + name + "]" ;
}
}
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Group.Java
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package com.company.entity;
import java.util.List;
public class Group {
private int id;
private String name;
private String position;
private List<Student> students;
public List<Student> getStudents() {
return students;
}
public void setStudents(List<Student> students) {
this .students = students;
}
public int getId() {
return id;
}
public void setId( int id) {
this .id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this .name = name;
}
public String getPosition() {
return position;
}
public void setPosition(String position) {
this .position = position;
}
@Override
public String toString() {
return "Group [id=" + id + ", name=" + name + ", position=" + position
+ "]" ;
}
}
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二、实体对应的表结构
student表:
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create table student(
id int primary key,
name varchar( 20 ),
birth date,
group_id int references g_group(g_id));
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g_group表:
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create table g_group(
g_id int primary key,
g_name varchar( 20 ),
g_position varchar( 30 ));
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sequence:
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create sequence student_id_sequence;
create sequence group_id_sequence;
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三、Student和Group的映射文件如下,你可以在映射文件中找到,关于MyBatis的增删改查操作,MyBatis调用存储过程,MyBatis分页以及MyBatis对一对一、多对多的处理
xml文件中都标有注释,看的时候配合下面的具体实现看,虽然有点乱
student.xml
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<?xml version= "1.0" encoding= "UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace= "com.company.dao.IStudentDAO" >
<!-- mybatis缓存 -->
<cache eviction= "LRU" flushInterval= "600000" size= "1024" readOnly= "false" />
<!-- sql标签用来定义一些可以被重用的sql语句或字段或片段等 -->
<sql id= "studentColumns" >select id,name,birth from student</sql>
<!-- 此处获得多对一的关系 ,但就单条记录而言却是一对一的关系,所以一对一的写法跟此相同-->
<resultMap type= "Student" id= "getStudentAndGroup" >
<id column= "id" property= "id" />
<result column= "name" property= "name" />
<result column= "birth" property= "birth" />
<association property= "group" column= "group_id" javaType= "Group" >
<id column= "g_id" property= "id" />
<result column= "g_name" property= "name" />
<result column= "g_position" property= "position" />
</association>
</resultMap>
<select id= "many2one" resultMap= "getStudentAndGroup" parameterType= "int" >
select s.id,s.name,s.birth,s.group_id,g.g_id,g.g_name,g.g_position
from student s
left join g_group g on s.group_id = g.g_id
where s.id = #{id}
</select>
<!-- 意图是获得一个学生,并且获得该学生所属的组,跟上面的意思差不多 ,用association的select属性-->
<!-- 于上面的相比个人感觉上面的效率要高些,因为上面只有一条sql语句 -->
<resultMap type= "Student" id= "getStudentAndGroupUseSelectMap" >
<id column= "id" property= "id" />
<result column= "name" property= "name" />
<result column= "birth" property= "birth" />
<association property= "group" column= "group_id" javaType= "Group" select= "selectGroup" />
</resultMap>
<select id= "getStudentAndGroupUseSelect" resultMap= "getStudentAndGroupUseSelectMap" parameterType= "int" >
select *
from student
where id = #{id}
</select>
<select id= "selectGroup" resultType= "Group" parameterType= "int" flushCache= "false" useCache= "true" ><!-- 此处实用缓存 -->
select g_id as id, g_name as name, g_position as position
from g_group
where g_id = #{id}
</select>
<!-- 动态sql语句 的测试dynamic sql-->
<select id= "getStudentBySomeCondition" parameterType= "Student" resultType= "Student" >
select *
from student
<where>
< if test= "id != null" >
id> 2
</ if >
< if test= "name != null" >
and name like '%g%'
</ if >
</where>
</select>
<!-- MyBatis调用存储过程 -->
<resultMap type= "Student" id= "studentMap" >
<id column= "id" property= "id" />
<result column= "name" property= "name" />
<result column= "birth" property= "birth" />
</resultMap>
<select id= "getAllUser" statementType= "CALLABLE" >
{call get_all_student(#{students ,mode=OUT, jdbcType=CURSOR, javaType=ResultSet, resultMap=studentMap} )}
</select>
<!-- MyBatis向student表中插入一条数据 -->
<insert id= "add" parameterType= "Student" keyColumn= "id" >
<selectKey keyProperty= "id" order= "BEFORE" resultType= "int" >
select stu_id_sequence.nextval from dual
</selectKey>
insert into student(id,name,birth) values(#{id},#{name},#{birth})
</insert>
<!-- 根据id获得学生的信息 -->
<select id= "getById" parameterType= "int" resultType= "Student" >
<include refid= "studentColumns" /> where id=#{id}
</select>
<!-- 此处的实现方法是一个分页的原型,请查看IStudentDAOImpl.java中的调用方法 -->
<select id= "getAllStudent" resultMap= "studentMap" >
<include refid= "studentColumns" /> order by id<!--此处是引用了上面预定义好的sql语句-->
</select>
</mapper>
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以上所述是小编给大家介绍的MyBatis存储过程、MyBatis分页、MyBatis一对多增删改查操作,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对服务器之家网站的支持!
原文链接:http://blog.csdn.net/bestlove12345/article/details/53258345