1.实现注解版MyBatis

@Mapper
public interface DepartmentMapper {
    @Select("select * from department where id=#{id}")
    public Department getDeptById(Integer id);

    @Delete("delete from department where id=#{id}")
    public int deleteDeptById(Integer id);

    @Options(useGeneratedKeys = true,keyProperty = "id")//标明自增id 
    @Insert("insert into department (departmentName) values (#{departmentName})")
    public int insertDept(Department department);

    @Update("update department set departmentName=#{departmentName} where id=#{id}")
    public int updateDept(Department department);
}

测试Controller

@RestController
public class DeptController {
    @Autowired
    DepartmentMapper departmentMapper;
    @GetMapping("/dept/{id}")
    public Department getDept(@PathVariable("id") Integer id){
        return departmentMapper.getDeptById(id);
    }
    @GetMapping("/dept")
    public Department insertDept(Department department) {
        departmentMapper.insertDept(department);
        return department;
    }
}

插入:http://localhost:8080/dept?departmentName=business

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查询:http://localhost:8080/dept/4

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自定义MyBatis的配置规则;给容器中添加一个ConfigurationCustomizer;

@Configuration
public class MybatisConfig {
    @Bean
    public ConfigurationCustomizer configurationCustomizer(){
        return new ConfigurationCustomizer() {
            @Override
            public void customize(Configuration configuration) {
                ///开启驼峰命名
                configuration.setMapUnderscoreToCamelCase(true);
            }
        };
    }
}

使用MapperScan批量扫描

@MapperScan(value = "com.xxx.mapper")//mapper所在的目录文件夹
@SpringBootApplication
public class JdbcdemoApplication {

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

2.配置文件版

mapper:

//@Mapper 或者 @MapperScan将接口扫描装配到容器中
public interface EmployeeMapper {
    public Employee getEmployeeById(Integer id);

    public void insertEmp(Employee employee);
}

application.yml 或者application.properties里面指定全局配置文件和sql映射文件位置

mybatis:
   config‐location: classpath:mybatis/mybatis‐config.xml 指定全局配置文件的位置
   mapper‐locations: classpath:mybatis/mapper/*.xml 指定sql映射文件的位置

全局配置文件:mybatis‐config.xml

<?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>
    <!--<settings>-->
        <!--<setting name="mapUnderscoreToCamelCase" value="true"/>-->
    <!--</settings>-->
</configuration>

指定sql映射文件

<?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.ari.ss.jdbcdemo.mapper.EmployeeMapper">
    <!--public Employee getEmployeeById(Integer id);-->
    <!--public void insertEmp(Employee employee);-->
    <select id="getEmployeeById" resultType="com.ari.ss.jdbcdemo.bean.Employee">
        select * from employee where id = #{id}
    </select>
    <insert id="insertEmp">
        insert into employee (lastName,email,gender,d_id) VALUES (#{lastName},#{email},#{gender},#{d_id})
    </insert>
</mapper>

测试同注解版