package com.mybatisstudy.pojo;
public class Teacher {
    private int id;
    private String teacherName;
    public Teacher(){
    }
    public Teacher(int id,String name){
        this.id = id;
        this.teacherName = name;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getTeacherName() {
        return teacherName;
    }
    public void setTeacherName(String teacherName) {
        this.teacherName = teacherName;
    }
    @Override
    public String toString() {
        return "Teacher[ " +
                "id=" + id +
                ", teacherName='" + teacherName + '\'' +
                " ]";
    }
}

package com.mybatisstudy.mapper;
import com.mybatisstudy.pojo.Teacher;
import java.util.List;
public interface TeacherMapper {
    // 查詢(xún)所有記錄
    List<Teacher> findAll();
}

<?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.mybatisstudy.mapper.TeacherMapper">
    <select id="findAll" resultType="com.mybatisstudy.pojo.Teacher">
        select * from teacher
    </select>
</mapper>

import com.mybatisstudy.mapper.TeacherMapper;
import com.mybatisstudy.pojo.Teacher;
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.After;
import org.junit.Before;
import org.junit.Test;
import java.io.InputStream;
import java.util.List;
public class TestTeacherMapper {
    InputStream is = null;
    SqlSession session = null;
    TeacherMapper teacherMapper = null;
    //前置方法，不必重復(fù)代碼
    @Before
    public void before() throws Exception {
        System.out.println("前置方法執(zhí)行·············");
        // （1）讀取核心配置文件
        is = Resources.getResourceAsStream("SqlMapConfig.xml");
        // （2）創(chuàng)建SqlSessionFactoryBuilder對(duì)象
        SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
        // （3）SqlSessionFactoryBuilder對(duì)象獲取SqlSessionFactory對(duì)象
        SqlSessionFactory factory = builder.build(is);
        // （4）SqlSessionFactory對(duì)象獲取SqlSession對(duì)象
        session = factory.openSession();
        // （5）SqlSession對(duì)象獲取代理對(duì)象
        teacherMapper = session.getMapper(TeacherMapper.class);
    }
    //后置方法，釋放資源
    @After
    public void after() throws Exception {
        System.out.println("后置方法執(zhí)行·············");
        session.close();
        is.close();
    }
    // 測(cè)試查詢(xún)所有教師方法
    @Test
    public void testFindAll(){
        List<Teacher> teachers = teacherMapper.findAll();
        teachers.forEach(System.out::println);
    }
}

    <select id="findAll" resultType="com.mybatisstudy.pojo.Teacher">
        select tid id, tname teacherName from teacher
    </select>

    <select id="findAll" resultMap="teacherMapper">
        select * from teacher
    </select>
    <resultMap id="teacherMapper" type="com.mybatisstudy.pojo.Teacher">
        <!-- id自定義主鍵列 properties：POJO屬性名 column:數(shù)據(jù)庫(kù)列名-->
        <id property="id" column="tid"></id>
        <!-- result定義普通列 property：POJO屬性名 column:數(shù)據(jù)庫(kù)列名-->
        <result property="teacherName" column="tname"></result>
    </resultMap>

// 根據(jù)ID查詢(xún)用戶(hù)
    Teacher findById(int id);

    <sql id="selectAllField">
        select tid id,tname teacherName
    </sql>
    <select id="findById" resultType="com.mybatisstudy.pojo.Teacher">
        <include refid="selectAllField"></include>
        from teacher where tid=#{id}
    </select>

// 測(cè)試根據(jù)ID查詢(xún)方法
    @Test
    public void testFindById(){
        int id = 3;
        Teacher teacher = teacherMapper.findById(id);
        System.out.println(teacher);
    }

// 查詢(xún)比輸入Id要大的記錄
    List<Teacher> findById2(int id);

    <select id="findById2" resultType="com.mybatisstudy.pojo.Teacher">
        <include refid="selectAllField"></include>
        from teacher where tid &gt; #{id}
    </select>

// 測(cè)試查詢(xún)比輸入Id大的記錄
    @Test
    public void testFindById2(){
        int id = 1;
        List<Teacher> teachers = teacherMapper.findById2(id);
        teachers.forEach(System.out::println);
    }