使用MyBatis框架实现对数据库增删改查

第一步：首先需要新建一个数据库，然后建一个表在表里面可以随便插入几条数据，不插入也可以，等下直接用程序插入，今天就用下面这个表举例

第二步：创建一个Java工程；

第三步：创建一个实体类User，将数据库中的字段名get、set。

package com.zhiyuan.pojo;public class User {    private int id;    private String name;    private String sex;    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 getSex() {        return sex;    }    public void setSex(String sex) {        this.sex = sex;    }}

第四步：写连接数据库的config.xml配置文件：

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "mybatis-3-config.dtd" ><configuration>    <typeAliases>        <typeAlias alias="User" type="com.zhiyuan.pojo.User"/>    </typeAliases>    <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://127.0.0.1:3306/mybatis" />                <property name="username" value="root" />                <property name="password" value="liuxi" />              </dataSource>        </environment>    </environments>    <mappers>        <mapper resource="com/zhiyuan/pojo/User.xml" />    </mappers></configuration>

第五步：配置对应实体类的user.XML文件，里面写MySQL增删改查语句：

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "mybatis-3-mapper.dtd" ><mapper namespace="com.zhiyuan.dao.Inter">    <!-- 插入数据，这里ID是自动递增的，所有不需要插入 -->    <insert id="getInsert" parameterType="User">        insert into nb(name,sex) values(#{name},#{sex})    </insert>    <!-- 查询表中所有的数据 -->    <select id="getUserList" resultType="com.zhiyuan.pojo.User">        select * from nb    </select>    <!-- 根据ID查询表数据 -->    <select id="getUser" parameterType="int" resultType="com.zhiyuan.pojo.User">        select * from nb where id=#{id}    </select>    <!-- 根据ID更新表数据 -->    <update id="getUpdate" parameterType="com.zhiyuan.pojo.User">        update nb set name=#{name},sex=#{sex} where id=#{id}    </update>    <!-- 根据ID删除表数据 -->    <delete id="getDelete" parameterType="int">        delete from nb where id=#{id}    </delete></mapper>

第六步：写对应user.xml的接口类。

package com.zhiyuan.dao;import java.util.List;import com.zhiyuan.pojo.User;public interface Inter {    public List<User> getUserList();    public User getUser(int id);    public void getInsert(User user);    public void getUpdate(User user);    public void getDelete(int id);}

最后一步写测试类：

package com.zhiyuan.main;import java.io.IOException;import java.io.Reader;import java.util.List;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 com.zhiyuan.dao.Inter;import com.zhiyuan.pojo.User;public class Main {    static SqlSessionFactory ssf;    static SqlSession ss;    public static void main(String[] args) throws IOException {        Reader re = Resources.getResourceAsReader("conf.xml");        ssf = new SqlSessionFactoryBuilder().build(re);        ss = ssf.openSession();        insert();//      userList();//      user();//      update();//      delete();    }    //根据ID删除字段    private static void delete() {        ss = ssf.openSession();        Inter ie = ss.getMapper(Inter.class);        ie.getDelete(1);        ss.commit();        System.out.println("删除后：");        userList();    }    //根据ID更新表数据    private static void update() {        ss = ssf.openSession();        Inter ite = ss.getMapper(Inter.class);        User us = ite.getUser(3);        us.setName("徐深何");        us.setSex("不详");        ite.getUpdate(us);        ss.commit();        System.out.println("更新后:");        userList();    }    //条件查询    private static void user() {        ss = ssf.openSession();        Inter it = ss.getMapper(Inter.class);        User user = it.getUser(3);        if(user != null){            System.out.println("姓名：" + user.getName());            System.out.println( "性别：" + user.getSex());        }    }    //查询全部    private static void userList() {        ss = ssf.openSession();        Inter is = ss.getMapper(Inter.class);        print(is.getUserList());    }    private static void print(List<User> userList) {        for(User us : userList){            System.out.println("编号：" + us.getId());            System.out.println("姓名：" + us.getName());            System.out.println("性别：" + us.getSex());        }    }    //插入    private static void insert() {        ss = ssf.openSession();        Inter in = ss.getMapper(Inter.class);        User user = new User();        user.setName("CSDN");        user.setSex("????");        in.getInsert(user);        ss.commit();        System.out.println("插入成功");        userList();    }}

最后输出结果为：

这里值得注意得到地方就是写配置文件时一定要细心，不然写到最后一运行一定会出现各种各样的错，找起来头痛。