用Pagehelper进行分页查询

controller:

@GetMapping public Result page(@RequestParam(defaultValue = "1") Integer page, @RequestParam (defaultValue = "10") Integer pageSize){ log.info("分页查询:{},{}",page,pageSize); PageResult pageResult = empService.page(page,pageSize); return Result.success(pageResult); }

Service:

//用PageHelper分页插件，导入依赖 @Override public PageResult<Emp> page(Integer page, Integer pageSize) { //设置分页参数(Pagehelper) PageHelper.startPage(page, pageSize); //执行查询 List<Emp> empList = empMapper.list(); //解析查询结果，并封装 Page<Emp> p = (Page<Emp>) empList; return new PageResult<Emp>(p.getTotal(),p.getResult()); }

Mapper:

@Mapper public interface EmpMapper { /*@Select("select count(*) from emp e left join dept d on e.dept_id = d.id") public Long count();*/ /* * 这里的d.name封装不到Emp对象中，所以需要使用别名解决 * */ /*@Select("select e.*,d.name deptName from emp e left join dept d on e.dept_id = d.id " + "order by e.update_time desc limit #{start},#{pageSize}") public List<Emp> list(Integer start, Integer pageSize);*/ @Select("select e.*,d.name deptName from emp e left join dept d on e.dept_id = d.id order by e.update_time desc") public List<Emp> list();