MyBatis Plus使用学习

1、配置数据库：

server:
  port: 8020
  
spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8
    username: root
    password: root

2、建立实体类：

public class User extends Model<User> {
    private static final long serialVersionUID = 1L;
    
    private Long id;
    private String name;
    private Integer age;
    private String email;
    .............
}

3、建立mapper文件：

public interface UserMapper extends BaseMapper<User> {
    .............
}

4、定义service：

public interface IUserService extends IService<User> {
    User getUserById(Long id);
}

@Service(value = "userService")
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements IUserService {

    @Resource
    private UserMapper userMapper;

    @Override
    public User getUserById(Long id) {
        return userMapper.selectById(id);
    }
}

5、实现controller：

@Controller
@RequestMapping("/user")
public class UserController {

    @Autowired
    private IUserService userService;

    @RequestMapping("/{id}")
    @ResponseBody
    public User getItem(@PathVariable(value = "id") Long id) {
        User user = userService.getUserById(id);
        return user;
    }
}

6、相关配置：

(1) Spring Boot配置：

配置@MapperScan注解，

@SpringBootApplication
@MapperScan("com.qingxuan.mybatis.plus.study.demo1")
public class MybatisPlusStudyDemo1Application {

    public static void main(String[] args) {
       SpringApplication.run(MybatisPlusStudyDemo1Application.class, args);
    }
}

(2) Spring MVC配置：

配置MapperScan：

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <!-- 自动扫描 com.imooc.dao下的interface,并加入IOC容器 -->
    <property name="basePackage" value="com.imooc.dao" />
    <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
</bean>

调整sqlSessionFactory为MyBatis Plus的sqlSessionFactory：

<bean id="sqlSessionFactory"
    class="com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <!-- 配置MyBatis的配置的文件 -->
    <property name="configLocation" value="classpath:mybatis.xml"></property>
    <!-- 注入MP的全局策略配置  -->
    <property name="globalConfig"  ref="globalConfiguration"></property>
    <!-- 插件注册 -->
    <property name="plugins">
       <list>
           <!-- 注册分页插件 -->
           <bean  class="com.baomidou.mybatisplus.plugins.PaginationInterceptor"></bean>
           <!-- 注册性能分析插件 -->
           <bean  class="com.baomidou.mybatisplus.plugins.PerformanceInterceptor">
               <property name="format" value="true"></property>
           </bean>
       </list>
    </property>
    
</bean>

参考资料：https://mp.baomidou.com/