mybatis 教程（一）

最新推荐文章于 2024-08-18 17:26:42 发布

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本文介绍了MyBatis的配置文件结构、实体类定义、Mapper接口实现以及如何通过MyBatis进行增删改查操作，包括添加用户、删除用户、更新用户信息和获取所有用户等功能。

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第一部：

<?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>

    <properties resource="db.properties"/>

<!-- 
    development : 开发模式
    work : 工作模式
 -->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="${driver}" />
                <property name="url" value="${url}" />
                <property name="username" value="${name}" />
                <property name="password" value="${password}" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/pdh/mybatis/domain/userMapper.xml"/>
    </mappers>
</configuration>

第二：user.java

package com.pdh.mybatis.domapublic class User {
private int id;

private String name;

private int age;

public User(int id, String name, int age) {
super();
this.id = id;
this.name = name;
this.age = age;
}

public User(String name, int age) {
super();
this.name = name;
this.age = age;
}

public User() {
super();
// TODO Auto-generated constructor stub
}

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 int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}

@Override
public String toString() {
return "User [id=" + id + ", name=" + name + ", age=" + age + "]";
}
}

<?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.pdh.mybatis.domain.userMapper">

    <!-- 
        curd
     -->
     <insert id="addUser" parameterType="com.pdh.mybatis.domain.User">
            insert into user(name,age) values(#{name},#{age});
     </insert>
     <delete id="delUser" parameterType="int">
            delete from user where id = #{id};
     </delete>
     <update id="updateUser" parameterType="com.pdh.mybatis.domain.User">
        update user set name=#{name} ,set age=#{age} where id = #{id};
     </update>

     <select id="getAllUser" resultType="com.pdh.mybatis.domain.User">
        select * from user;
     </select>
    <!-- 
        根据id查询得到一个user对象
     -->
     <select id="getUser" parameterType="int" resultType="com.pdh.mybatis.domain.User">
        select * from user where id=#{id}
     </select>
</mapper>

第四：

package com.pdh.mybatis.domain;

import java.io.InputStream;
import java.util.List;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test;

public class TestUser  {

    private SqlSessionFactory sessionFactory;

    @Before
    public void  init(){
        String resource = "conf.xml";
        InputStream inputStream = TestUser.class.getClassLoader().getResourceAsStream(resource);//类加载器去加载配置文件
         this.sessionFactory= new SqlSessionFactoryBuilder().build(inputStream);//创建session  
    }
    @Test
    public void findOneUser() {

        SqlSession session = this.sessionFactory.openSession();

        String statement = "com.pdh.mybatis.domain.userMapper.getUser";
        User user = session.selectOne(statement,1);
        System.out.println(user);
    }
    @Test
    public void addUser(){
        SqlSession session = this.sessionFactory.openSession();
        String statement = "com.pdh.mybatis.domain.userMapper.addUser";
        int instertcunt = session.insert(statement, new User("彭登浩",25));
        session.commit();
        session.close();
        System.out.println(instertcunt);
    }

    @Test
    public void delUser(){
        SqlSession session = this.sessionFactory.openSession();
        String statement = "com.pdh.mybatis.domain.userMapper.delUser";
        int delcount = session.delete(statement, 1);
        session.commit();
        session.close();
        System.out.println(delcount);
    }
    @Test
    public void getAllUser(){
        SqlSession session = this.sessionFactory.openSession();
        String statement = "com.pdh.mybatis.domain.userMapper.getAllUser";
        List<User>  users = session.selectList(statement);
        System.out.println(users);
    }
}