增删改查
1.在接口中定义方法
package com.kuang.dao;import com.kuang.pojo.User;import java.util.List;public interface UserMapper { List<User>getUserList(); //依据id查问用户 User getUserById(int id); //插入一个用户 int addUser(User user); //批改用户信息 void updateUser(User user); //删除用户信息 int deleteUser(int id);}2.在Usermapper.xml文件中绑定办法
<?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.kuang.dao.UserMapper"> <select id="getUserList" resultType="com.kuang.pojo.User"> select * from mybaits.user; </select> <select id="getUserById" resultType="com.kuang.pojo.User" parameterType="int"> select *from mybaits.user where id=#{id} </select> <insert id="addUser" parameterType="com.kuang.pojo.User" > insert into mybaits.user(id, name, password) values (#{id},#{name},#{password}); </insert> <update id="updateUser" parameterType="com.kuang.pojo.User" > update mybaits.user set name=#{name}, password=#{password} where id=#{id}; </update> <delete id="deleteUser" parameterType="int"> delete from mybaits.user where id=#{id} </delete></mapper>**namespace中写xml文件的绝对路径
id填办法名 留神要和接口中的办法名统一 不能有空格！！！
resultType写实体类的绝对路径**
3.在测试类中写办法
@Testpublic void test(){//获取sqlsession实例对象//SqlSession 提供了在数据库执行 SQL 命令所需的所有办法 SqlSession sqlSession = MybatisUtils.getSqlSession();//通过映射类并将已映射的 select 语句匹配到对应名称、参数和返回类型的办法UserMapper userDao = sqlSession.getMapper(UserMapper.class); List<User> userList = userDao.getUserList(); for (User user : userList) { System.out.println(user); }//敞开流sqlSession.close();