目标
- 利用MybatisPlus提供的IService接口和ServiceImpl类更方便的创建自定义Service;
方法
- 创建UserService接口并继承在IService;
import com.baomidou.mybatisplus.extension.service.IService; import edu.sctu.demo.mybatis.plus.model.UserEntity; public interface UserService extends IService<UserEntity> { }
- 创建接口的实现类UserServiceImpl；
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; import edu.sctu.demo.mybatis.plus.mapper.UserMapper; import edu.sctu.demo.mybatis.plus.model.UserEntity; import edu.sctu.demo.mybatis.plus.service.UserService; import org.springframework.stereotype.Service; @Service public class UserServiceImpl extends ServiceImpl<UserMapper, UserEntity> implements UserService { }
- 使用UserService提供的更加丰富的功能；
@SpringBootApplication public class Application implements CommandLineRunner { @Autowired(required = false) private UserMapper userMapper; @Autowired private UserService userService; public static void main(String[] args) { SpringApplication.run(Application.class, args); } @Override public void run(String... args) throws Exception { System.out.println(userMapper.selectList(null)); // 带条件的查询 QueryWrapper<UserEntity> queryWrapper = new QueryWrapper<>(); queryWrapper.eq("username", "chen"); System.out.println(userMapper.selectList(queryWrapper)); System.out.println(userService.count()); } }
结语
本文介绍了利用MybatisPlus提供的IService接口以及ServiceImpl通用类提供的丰富的方法，更加便捷的用于操作数据库。
