SpringBoot整合MyBatis

整合MyBatis

官方文档：http://mybatis.org/spring-boot-starter/mybatis-spring-boot-autoconfigure/

Maven 仓库地址：
https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter/2.1.1
1、包结构

一、整合包，导入依赖

<dependencies>

    <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.22</version>
        <scope>provided</scope>
    </dependency>


    <!-- 整合/mybatis-spring-boot-starter -->
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.2.2</version>
    </dependency>
    
	<!-- 连接数据库 -->
	<dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
</dependencies>

二、配置数据库

在application.properties中配置mybatis

spring.datasource.username=root
spring.datasource.password=root
spring.datasource.url=jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver


#整合MyBatis
mybatis.type-aliases-package=com.baidu.pojo
mybatis.mapper-locations=classpath:mybatis/mapper/ *.xml #映射mapper文件

三、创建实体类

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {

    private int id;
    private String name;
    private String pwd;


}

四、编写Sql语句；

创建一个mapper的包，编写一个userMapper接口

//这个注解表示了这是一个MyBatis的mapper类
@Mapper
@Repository  //被Spring管理
public interface UserMapper {

    //查询全部用户；
    List<User> queryUserList();

    //根据ID查询用户；
    User queryUserById(int id);

    //添加一个用户
    int addUser(User user);

    //更新一个用户
    int updateUser(User user);

    //删除一个用户
    int deleteUser(int id);

}

五、编写SQl

<?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">

	<!--绑定UserMapper-->
    <mapper namespace="com.baidu.mapper.UserMapper">

        <select id="queryUserList" resultType="user">
            select * from mybatis.user
        </select>

        <select id="queryUserById" resultType="user">
            select * from mybatis.user where id = #{id}
        </select>

        <insert id="addUser" parameterType="user">
            insert into mybatis.user (id,name,pwd) values (#{id},#{name},#{pwd})
        </insert>

        <update id="updateUser" parameterType="user">
            update mybatis.user set name=#{name},pwd=#{pwd} where id = #{id}
        </update>

        <delete id="deleteUser" parameterType="int">
            delete from user where is = #{id}
        </delete>

    </mapper>

六、测试

Controller层调用Dao层

package com.baidu.controller;

import com.baidu.mapper.UserMapper;
import com.baidu.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class UserController {


    @Autowired
    UserMapper userMapper;

    @GetMapping("/queryUserList")
    public List<User> queryUserList() {
        List<User> userList = userMapper.queryUserList();
        for (User user : userList) {
            System.out.println(user);
        }

        return userList;
    }

    //根据ID查询用户；
    @GetMapping("/queryById")
    public String queryById() {

        User user = userMapper.queryUserById(2);
        System.out.println(user);
        return "OK";
    }

    //添加一个用户
    @GetMapping("/addUser")
    public String addUser() {
        userMapper.addUser(new User(4, "铁锤", "123123"));
        return "oK";
    }

    //更新一个用户
    @GetMapping("/updateUser")
    public String updateUser() {
        userMapper.updateUser(new User(1, "幺鸡", "123456"));
        return "OK";
    }

    //删除一个用户
    @GetMapping("/deleteUser")
    public String deleteUser() {
        userMapper.deleteUser(5);
        return "OK";
    }
}

测试成功：