springboot使用mybatis

引入maven依赖

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- SpringBoot web组件 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- mybatis 支持 SpringBoot -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.0</version>
        </dependency>
        <!-- mysql 驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.31</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.51</version>
        </dependency>

新增数据库配置

server.port=8080

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/demomybatis?characterEncoding=utf-8&serverTimezone=UTC&useSSL=false
spring.datasource.username=xx
spring.datasource.password=xx
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true

mybatis.mapper-locations = classpath:mapping/*Mapper.xml

创建数据库表

Person数据库如下图

Address数据库如下图

实体类

@Data
public class Person {

    private String id;

    private String name;

}

@Data
public class Address {

    private String id;

    private String addrName;

}

编写mapper接口层

通过xml文件

@Mapper //表示这是Mybatis的mapper类
@Repository
public interface PersonMapper {

    List<Person> queryUserList();

    Person queryUserByID(String id);

    int addUser(Person person);

    int updateUser(Person person);

    int deleteUser(String id);

}

mapper中直接使用注解

@Mapper //表示这是Mybatis的mapper类
@Repository
public interface AddressMapper {

    @Select("SELECT * FROM address WHERE addrName = #{name}")
    Address findByName(@Param("name") String name);

    @Insert("INSERT INTO address VALUES (#{id}, #{addrName},)")
    int insert(@Param("id") String id, @Param("addrName") String addrName);
}

编写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.example.demo.PersonMapper">
    <select id="queryUserList" resultType="com.example.demo.Person">
        select * from person
    </select>

    <select id="queryUserByID" resultType="com.example.demo.Person">
        select * from person where id= #{id}
    </select>

    <insert id="addUser" parameterType="com.example.demo.Person">
        insert into person(id,name) values (#{id},#{name})
    </insert>

    <update id="updateUser" parameterType="com.example.demo.Person">
        update person set name=#{name} where id=#{id}
    </update>

    <delete id="deleteUser" parameterType="java.lang.String">
        delete from person where id=#{id}
    </delete>
</mapper>

IDEA创建mybatis的xml文件

File---->Settings

Editor---->File And Code Templates —>中间选中Files ----->点击+号，添加模板 ----->输入模板名字：Name:XML File.xml （name可以自定义） ------>后缀名extension：xml

在面板中间输入内容

<?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="">

</mapper>

选中文件夹----->New-------->找到XML File，就可以创建xml文件了

parameterType

Mybatis的Mapper文件中的select、insert、update、delete元素中有一个parameterType属性，用于对应的mapper接口方法接受的参数类型

启动类

在启动类里加上注解用于给出需要扫描的mapper文件路径@MapperScan

@SpringBootApplication
@MapperScan("com.example.demo")
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}

controller调用

@CrossOrigin
@RestController
@RequestMapping("/define")
public class DemoController {

    @Autowired
    PersonMapper personMapper;

    @GetMapping("/getmybatis")
    public List<Person> getmybatis() {
        List<Person> res= personMapper.queryUserList();
        return res;
    }

    @GetMapping("/queryUserList")
    public List<Person> queryUserList() {
        List<Person> users = personMapper.queryUserList();
        return users;
    }

    @GetMapping("/queryUserByID")
    public Person queryUserByID() {
        Person user = personMapper.queryUserByID("2");
        return user;
    }

    @GetMapping("/addUser")
    public String addUser() {
        Person p = new Person();
        p.setId("4");
        p.setName("zzz");
        personMapper.addUser(p);
        return "增加用户完毕";
    }

    @GetMapping("/updateUser")
    public String updateUser() {
        Person p = new Person();
        p.setId("2");
        p.setName("zzz");
        personMapper.updateUser(p);
        return "修改用户完毕";
    }

    @GetMapping("/deleteUser")
    public String deleteUser() {
        personMapper.deleteUser("4");
        return "删除用户完毕";
    }

    @Autowired
    AddressMapper addressMapper;

    @RequestMapping("/addAddress")
    public int addUser(String userName, String age) {
        
        return addressMapper.insert(age,userName);
    }

    @RequestMapping("/getAddress")
    public Address getUserByName(String userName) {
        
        return addressMapper.findByName(userName);
    }
}