Mybatis实例：
对两个表Student、StudentInfo的CRUD操作
在Src目录下建一个mybatis的xml配置文件mybatis.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- 引入外部 -->
<properties resource="db.properties"></properties>
<!-- 定义别名 -->
<typeAliases>
<!-- 自动扫描 -->
<package name="com.model"/>
</typeAliases>
<environments default="development">
<environment id="development">
<!-- 事务管理器 -->
<transactionManager type="JDBC"></transactionManager>
<!-- 数据源 -->
<dataSource type="POOLED">
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
<property name="url" value="${url}"/>
<property name="driver" value="${driver}"/>
</dataSource>
</environment>
</environments>
<!-- 扫描包下的接口 -->
<mappers>
<package name="com.dao"/>
</mappers>
</configuration>
定义Student mappers、StudentInfo mappers的StudentMapper.xml、StudentInfoMapper.xml配置文件和StudentMapper、StudentInfoMapper接口
StudentMapper接口
package com.dao;
import java.util.List;
import java.util.Map;
import com.model.Student;
public interface StudentMapper {
public Integer add(Student stu);
public void del(String sno);
public void update(Student stu);
public Student show(String sno);
public List<Student> showMany(Map<String,Object> map);
}
StudentInfoMapper接口
package com.dao;
import java.util.List;
import com.model.Studentinfo;
public interface StudentInfoMapper {
public List<Studentinfo> sel();
}
StudentMapper.xml配置文件：
<?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.dao.StudentMapper">
<resultMap type="student" id="stulist"></resultMap>
<insert id="add" parameterType="student">
insert into student values(#{sno},#{sname},#{ssex},sysdate,#{sclass})
</insert>
<delete id="del" parameterType="String">
delete student s where s.sno=#{sno}
</delete>
<update id="update" parameterType="student">
update student t set t.sname=#{sname},t.ssex=#{ssex}
,t.sbirthday=sysdate,t.sclass=#{sclass} where t.sno=#{sno}
</update>
<select id="show" resultType="student" parameterType="String">
select * from student s where s.sno=#{sno}
</select>
<select id="showMany" resultMap="stulist" parameterType="Map">
select * from student s where s.sname like #{p1} and s.ssex=#{p2}
</select>
</mapper>
StudentInfoMapper.xml配置文件
<?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.dao.StudentInfoMapper"> <!-- 查询两个表的关联 方法一 <resultMap type="studentinfo" id="stuinfo"> <id property="id" column="id"/> <result property="student.sno" column="sno"/> <result property="student.sname" column="sname"/> <result property="student.ssex" column="ssex"/> <result property="student.sbirthday" column="sbirthday"/> <result property="student.sclass" column="sclass"/> <result property="saddress" column="saddress"/> </resultMap> --> <!-- 查询两个表的关联 方法二 --> <resultMap type="studentinfo" id="stuinfo"> <association property="student" column="sno" select="com.dao.StudentMapper.show"></association> </resultMap> <select id="sel" resultMap="stuinfo"> select * from studentinfo si left join student s on si.sno=s.sno </select> </mapper>
配置文件实现了接口和SQL语句的映射关系。
Student类和StudentInfo类的实体类：
Student类：
package com.model;
import java.util.Date;
public class Student {
private String sno;
private String sname;
private String ssex;
private Date sbirthday;
private String sclass;
public Student() {
super();
}
public Student(String sno, String sname, String ssex, Date sbirthday, String sclass) {
super();
this.sno = sno;
this.sname = sname;
this.ssex = ssex;
this.sbirthday = sbirthday;
this.sclass = sclass;
}
public String getSno() {
return sno;
}
public void setSno(String sno) {
this.sno = sno;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
public String getSsex() {
return ssex;
}
public void setSsex(String ssex) {
this.ssex = ssex;
}
public Date getSbirthday() {
return sbirthday;
}
public void setSbirthday(Date sbirthday) {
this.sbirthday = sbirthday;
}
public String getSclass() {
return sclass;
}
public void setSclass(String sclass) {
this.sclass = sclass;
}
@Override
public String toString() {
return "Student [sno=" + sno + ", sname=" + sname + ", ssex=" + ssex + ", sbirthday=" + sbirthday + ", sclass="
+ sclass + "]";
}
}
StudentInfo类：
package com.model;
public class Studentinfo {
private Integer id;
private Student student;
private String saddress;
public Studentinfo() {
super();
}
public Studentinfo(Integer id, Student student, String saddress) {
super();
this.id = id;
this.student = student;
this.saddress = saddress;
}
@Override
public String toString() {
return "Studentinfo [id=" + id + ", student=" + student + ", saddress=" + saddress + "]";
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public Student getStudent() {
return student;
}
public void setStudent(Student student) {
this.student = student;
}
public String getSaddress() {
return saddress;
}
public void setSaddress(String saddress) {
this.saddress = saddress;
}
}
为了方便写一个工具类SqlSessionUtil 拿出session：
package com.util;
import java.io.IOException;
import java.io.InputStream;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
/**
* Mybatis工具类
* @return
*/
public class SqlSessionUtil {
private static SqlSessionFactory ssf;
private static SqlSession ss;
/**
* 获取Mybatis核心SQLsessionFactory
* @return
*/
public static SqlSessionFactory getSQLSessionFactory(){
InputStream in = null;
try {
in = Resources.getResourceAsStream("mybatis-config.xml");
ssf = new SqlSessionFactoryBuilder().build(in);
in.close();
} catch (IOException e) {
e.printStackTrace();
}
return ssf;
}
/**
* 获取SQLsession
* @return
*/
public static SqlSession getSQLSession(){
ss = getSQLSessionFactory().openSession();
return ss;
}
}
Junit测试类：
package com.test;
import static org.junit.Assert.*;
import java.util.List;
import org.apache.ibatis.session.SqlSession;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.dao.StudentInfoMapper;
import com.model.Studentinfo;
import com.util.SqlSessionUtil;
public class StudentInfoJunit {
private SqlSession ss;
private StudentInfoMapper sm;
@Before
public void setUp() throws Exception {
ss= SqlSessionUtil.getSQLSession();
sm = ss.getMapper(StudentInfoMapper.class);
}
@After
public void tearDown() throws Exception {
ss.commit();
ss.close();
}
@Test
public void test() {
List<Studentinfo> list = sm.sel();
for(Studentinfo sinfo : list){
System.out.println(sinfo);
}
}
}
运行结果如下（实现的两表一对一）：
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