Mybatis 02 对数据的CRUD(增删改查) 操作

1.导包

2.配置文件

<?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>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver"                        value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://localhost:3308/mybatis" />
                <property name="username" value="root" />
                <property name="password" value="210374520" />
            </dataSource>
        </environment>
    </environments>

</configuration>

3.创建实体类

package com.dhl.beyond.shiyan1;

public class User {
    private int id;  //用户的Id 或者是 学号
    private String name; //姓名
    private int age; //年龄

    public User() {
    }

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

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

    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;
    }
}

4.创建Mapper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.dhl.beyond.shiyan3.userMapper">
    <select id="selectUser" parameterType="int" resultType="com.dhl.beyond.shiyan1.User">
        select * from users where id=#{id}
    </select>

    <insert id="insertUser" parameterType="com.dhl.beyond.shiyan1.User">
        insert into users(name,age) values(#{name},#{age})
    </insert>

    <update id="updateUser" parameterType="com.dhl.beyond.shiyan1.User">
        update users set name =#{name},age=#{age} where id = #{id}
    </update>

    <delete id="deleteUser" parameterType="int">
        delete from users where id=#{id}
    </delete>
</mapper>

5.注册

<mapper resource="com/dhl/beyond/shiyan3/userMapper.xml"/>

6.测试类

package com.dhl.beyond.shiyan3;

import com.dhl.beyond.shiyan1.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

import java.io.IOException;
import java.io.Reader;

public class TestUser {
    @Test
    public void testSelectUser() throws IOException {
        String resource = "config.xml";
        Reader reader = Resources.getResourceAsReader(resource);
        SqlSessionFactory sqlSessionFactory =  new SqlSessionFactoryBuilder().build(reader);
        SqlSession session = sqlSessionFactory.openSession();
        String s = "com.dhl.beyond.shiyan3.userMapper.selectUser";
        User o = session.selectOne(s, 2);
        System.out.println(o);
    }

    @Test
    public void testInsertUser() throws IOException {
        String resouce = "config.xml";
        Reader reader = Resources.getResourceAsReader(resouce);
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(reader);
        String s = "com.dhl.beyond.shiyan3.userMapper.insertUser";
        SqlSession session = factory.openSession();
        User u = new User();
        u.setAge(20);
        u.setName("zhangsan");
        int insert = session.insert(s, u);
        System.out.println(insert);
    }

    @Test
    public void testUpdateUser() throws IOException {
        String resource = "config.xml";
        Reader reader = Resources.getResourceAsReader(resource);
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(reader);
        SqlSession session = factory.openSession();
        String s = "com.dhl.beyond.shiyan3.userMapper.updateUser";
        int update = session.update(s, new User(2, "lisi", 22));
        System.out.println(update);

    }

    @Test
    public void testDeleteUser() throws IOException{
        String resource = "config.xml";
        Reader reader = Resources.getResourceAsReader(resource);
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(reader);
        SqlSession session = factory.openSession();
        int delete = session.delete("com.dhl.beyond.shiyan3.userMapper.deleteUser", 3);
        System.out.println(delete);

    }
}

7.结果集

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目录结构