1、匯入jar包

　　　　　　<!--mybatis連線mysql-->
		<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>1.3.2</version>
		</dependency>

		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
		</dependency>

		<dependency>
			<groupId>org.mybatis</groupId>
			<artifactId>mybatis</artifactId>
			<version>3.4.0</version>
		</dependency>

　2、在application.yml配置資料來源（此處是mysql）和 mybatis

#連線資料庫
spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/demo?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&serverTimezone=UTC
    hikari:
      username: root
      password: 123456


mybatis:
  #配置mapper對映檔案 classpath代表resources下
  mapper-locations: classpath:mapper/*.xml
  #開啟sql執行日誌
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    #所有pojo類所在包路徑
  type-aliases-package: com.wwc.demo.pojo

3、建立實體類物件

public class UserInfo {

    private int id;

    private String userName;

    private String userPwd;

    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 String getUserPwd() {
        return userPwd;
    }

    public void setUserPwd(String userPwd) {
        this.userPwd = userPwd;
    }

    public UserInfo(int id, String userName, String userPwd) {
        this.id = id;
        this.userName = userName;
        this.userPwd = userPwd;
    }

    public UserInfo() {
    }

    @Override
    public String toString() {
        return "UserInfo{" +
                "id=" + id +
                ", userName='" + userName + '\'' +
                ", userPwd='" + userPwd + '\'' +
                '}';
    }
}

　4、建立dao層使用註解@Mapper

@Mapper
public interface UserInfoDao {

    List<UserInfo> getList();
}

5、建立mybatis對映檔案mapper.xml

<?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.wwc.demo.dao.UserInfoDao">
　　<!-- 結果集與實體類對映-->
    <resultMap id="userInfoMap" type="com.wwc.demo.pojo.UserInfo">
        <id property="id" column="id" javaType="int" jdbcType="INTEGER"></id>
        <result property="userName" column="user_name" javaType="String" jdbcType="VARCHAR"></result>
        <result property="userPwd" column="user_pwd" javaType="String" jdbcType="VARCHAR"></result>
    </resultMap>

    <select id="getList" resultMap="userInfoMap">
        select * from user_info
    </select>
</mapper>

6、資料庫建立對應的表

7、啟動測試成功