Spring Boot 集成 Mybatis 注解方式

1. 注解方式

1.1 配置

mybatis:
  configuration:
    map-underscore-to-camel-case: true

# 打印sql
logging:
  level:
    com.concrete.boot.dao.mapper: DEBUG

1.2 Mapper 接口

@Mapper
public interface OrderDao {

    @Select("select * from con_order")
    List<Order> findAll();

    @Select("select * from con_order where id = #{id}")
    Order queryOrderById(@Param("id") Integer id);
}

1.3 启动类 @MapperScan

@SpringBootApplication(scanBasePackages = "com.example.conboot.starter")
@MapperScan(basePackages = "com.concrete.boot.dao.mapper")
public class ConbootStarterApplication {
    public static void main(String[] args) {
        SpringApplication.run(ConbootStarterApplication.class, args);
    }
}

2. 其他注解

@Alias

3. Mybatis

3.1 resultType vs resultMap

3.2 # vs $

4. 分页助手

<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper-spring-boot-starter</artifactId>
    <version>1.4.5</version>
</dependency>

@Slf4j
@RestController
public class DaoController {
    @Resource
    private OrderDao orderDao;

    @RequestMapping("/order/list")
    public String queryOrders() {
        List<Order> orders = orderDao.findAll();
        return JSON.toJSONString(orders);
    }

    @RequestMapping("/order/list/{page}")
    public String queryOrdersByPage(@PathVariable Integer page) {
        // 1. 分页
        PageHelper.startPage(page, 3);
        // 2. 查询
        List<Order> orders = orderDao.findAll();
        // 3. 封装PageInfo
        PageInfo<Order> pageInfo = new PageInfo<>(orders);
        // 4. 输出 pageInfo.getList()
        return JSON.toJSONString(pageInfo.getList());
    }
}

请求地址：http://localhost:8080/order/list/1

5. 注解和 xml 混用

既有注解又有 xml 配置时，不要配置 mybatis-config.xml, 单独配置mapper.xml

mybatis:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.concrete.boot.dao.entity
  configuration:
    map-underscore-to-camel-case: true