student_system/springboot/src/main/java/com/example/service/CourseService.java

package com.example.service;

import com.example.entity.Course;
import com.example.mapper.CourseMapper;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;

@Service
public class CourseService {
         @Resource
         private CourseMapper courseMapper;


       //total是查询总数 list是数据列表
       public PageInfo<Course> selectPage(Integer pageNum, Integer pageSize,Course course){
           PageHelper.startPage(pageNum,pageSize);
           List<Course> coursesList = courseMapper.selectAll(course);
           return PageInfo.of(coursesList);
       }
    //新增数据
    public void add(Course course) {
           courseMapper.insert(course);
    }

    public void updateById(Course course) {
           courseMapper.updateById(course);
    }

    public void deleteById(Integer id) {
           courseMapper.deleteById(id);
    }
}