-- 創(chuàng)建用戶表
create table user (
 id int primary key auto_increment,
 username varchar(20) not null,
 birthday date,
 sex char(1) default '男',
 address varchar(50)
);

-- 添加用戶數(shù)據(jù)
insert into user values (null, '孫悟空','1980-10-24','男','花果山水簾洞');
insert into user values (null, '白骨精','1992-11-12','女','白虎嶺白骨洞');
insert into user values (null, '豬八戒','1983-05-20','男','福臨山云棧洞');
insert into user values (null, '蜘蛛精','1995-03-22','女','盤絲洞');

-- 查詢用戶數(shù)據(jù)
select * from user;

package com.vg.entity;

import java.util.Date;

public class User {
  private int id;
  private String username;
  private Date birthday;
  private String sex;
  private String address;

  //alt+insert快速生成getter/setter方法
  public int getId() {
    return id;
  }

  public void setId(int id) {
    this.id = id;
  }

  public String getUsername() {
    return username;
  }

  public void setUsername(String username) {
    this.username = username;
  }

  public Date getBirthday() {
    return birthday;
  }

  public void setBirthday(Date birthday) {
    this.birthday = birthday;
  }

  public String getSex() {
    return sex;
  }

  public void setSex(String sex) {
    this.sex = sex;
  }

  public String getAddress() {
    return address;
  }

  public void setAddress(String address) {
    this.address = address;
  }

  @Override
  public String toString() {
    return "User{" +
        "id=" + id +
        ", username='" + username + '\'' +
        ", birthday=" + birthday +
        ", sex='" + sex + '\'' +
        ", address='" + address + '\'' +
        '}';
  }
}

package com.vg.dao;
import com.vg.entity.User;
import java.util.List;
/**
 * 數(shù)據(jù)訪問(wèn)層接口:對(duì)用戶進(jìn)行增刪改查操作
 * */
public interface UserMapper {
  /**
   * 查詢所有用戶
   * */
  List<User> findAllUsers();
}

<?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>
  
</mapper>

<?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>
  
</configuration>

package com.vg.test;
import org.junit.Test;
/**
 * 測(cè)試類
 */
public class TestUserMapper {

  /**
   * 測(cè)試方法：查詢所有學(xué)生
   */
  @Test
  public void testFindAllUsers(){
    
  }
}

<?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標(biāo)簽作用:配置數(shù)據(jù)庫(kù)環(huán)境
    default:設(shè)置默認(rèn)的數(shù)據(jù)庫(kù)環(huán)境
    environment:用來(lái)配置一個(gè)數(shù)據(jù)庫(kù)的環(huán)境信息
  -->
  <environments default="develop">
    <!--用來(lái)配置一個(gè)數(shù)據(jù)庫(kù)的環(huán)境信息
      id:配置環(huán)境信息的唯一標(biāo)識(shí)
    -->
    <environment id="develop">
      <!--
        transactionManager:配置事務(wù)管理器
          type:設(shè)置事務(wù)管理器的類型,取值有type=“[JDBC|MANAGED]”
            JDBC:事務(wù)管理使用JDBC的管理方式
            MANAGED:事務(wù)交給容器管理(mybatis不管理),后續(xù)交給spring容器管理。

      -->
      <transactionManager type="JDBC"></transactionManager>
      <!--
        dataSource:配置數(shù)據(jù)源(連接池)信息
          type:設(shè)置數(shù)據(jù)源類型,常用的值有:unpooled 和 pooled
            unpooled:不使用連接池,每次都重新獲取連接操作數(shù)據(jù)
            pooled:使用mybatis內(nèi)置的連接池
      -->
      <dataSource type="POOLED">
        <!--數(shù)據(jù)庫(kù)驅(qū)動(dòng)字符串-->
        <property name="driver" value="com.mysql.jdbc.Driver"/>
        <!--數(shù)據(jù)庫(kù)驅(qū)動(dòng)字符串-->
        <property name="url" value="jdbc:mysql://localhost:3306/test"/>
        <!--用戶名-->
        <property name="username" value="root"/>
        <!--密碼-->
        <property name="password" value="root"/>
      </dataSource>
    </environment>
  </environments>
</configuration>

<?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">
<!--
  映射的作用：一個(gè)映射文件就對(duì)應(yīng)一個(gè)接口，一個(gè)接口可以有多個(gè)映射文件，一般是一對(duì)一關(guān)系。
  mapper標(biāo)簽的namespace屬性的作用：關(guān)聯(lián)接口，需要配置對(duì)應(yīng)接口的類全名字符串
-->
<mapper namespace="com.vg.dao.UserMapper">
  <!-- 完成接口映射配置文件UserMapper.xml的編寫(xiě)：這個(gè)映射文件就相當(dāng)于UserMapper接口實(shí)現(xiàn)類配置 -->

  <!--select標(biāo)簽的作用：用來(lái)配置查詢要執(zhí)行的SQL語(yǔ)句
    id屬性：關(guān)聯(lián)接口中的方法名
    resultType屬性：設(shè)置方法返回的數(shù)據(jù)類型，如果是集合則配置集合元素的類型
  -->
  <select id="findAllUsers" resultType="com.vg.entity.User">
    select * from user
  </select>
</mapper>

 <!--mappers標(biāo)簽的作用:用來(lái)配置接口映射文件-->
  <mappers>
    <!--mapper標(biāo)簽:一個(gè)該標(biāo)簽就配置一個(gè)接口映射文件
      resource屬性:配置映射文件的路徑,路徑分隔符使用 / : com/vg/dao/UserMapper.xml
      url:用于配置互聯(lián)網(wǎng)上的映射文件的路徑,比如:http://www.baidu.com/xxx.xml
    -->
    <mapper resource="com/vg/dao/UserMapper.xml"></mapper>
  </mappers>

package com.vg.test;

import com.vg.dao.UserMapper;
import com.vg.entity.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.InputStream;
import java.util.List;

/**
 * 測(cè)試類
 */
public class TestUserMapper {
  /**
   * 測(cè)試方法:查詢所有學(xué)生
   * SqlSessionFactoryBuilder=>SqlSessionFactory=>Sqlsession:相當(dāng)于JDBC中的Connection對(duì)象
   */
  @Test
  public void testFindAllUsers() throws Exception{
    //1. 通過(guò)Resources類，加載sqlMapConfig.xml，得到文件輸入流對(duì)象
    // Resources類作用：專門讀取src目錄下的資源文件
    InputStream in = Resources.getResourceAsStream("sqlMapConfig.xml");
    //2. 實(shí)例化會(huì)話工廠創(chuàng)建類SqlSessionFactoryBuilder
    SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
    //3. 通過(guò)會(huì)話工廠創(chuàng)建類，讀取上面的輸入流，得到會(huì)話工廠SqlSessionFactory類
    SqlSessionFactory sqlSessionFactory = builder.build(in);
    //4. 使用SqlSessionFactory對(duì)象，創(chuàng)建SqlSession對(duì)象
    //a) 它相當(dāng)于JDBC中的Connection對(duì)象，提供了操作數(shù)據(jù)庫(kù)的CRUD方法
    //b) 它提供了一個(gè)getMapper()方法，獲取接口的實(shí)現(xiàn)對(duì)象。
    SqlSession sqlSession = sqlSessionFactory.openSession();
    //5. 獲取接口 UserMapper 實(shí)現(xiàn)類對(duì)象
    UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
    System.out.println("userMapper = " +userMapper);
    //6. 執(zhí)行數(shù)據(jù)庫(kù)的查詢操作，輸出用戶信息
    List<User> userList = userMapper.findAllUsers();
    for (User user : userList) {
      System.out.println(user);
    }
    //7. 關(guān)閉會(huì)話，釋放資源。
    sqlSession.close();
  }
}