麻烦大哥帮我解读下这段语句，顺便讲解下待处理是如何显示给当前用户的

<select id="selectByNextDealSn" resultMap="claimVoucher" parameterType="String">
    select cv.*,ce.name cname,ce.post cpost,d.name dname,d.post dpost
    from claim_voucher cv
    left join employee ce on ce.sn=cv.create_sn
    left join employee d on d.sn = cv.next_deal_sn
    where cv.next_deal_sn=#{ndsn} order by cv.create_time desc
</select>

假如我登录的是经理账号，那是哪一段语句控制只显示给经理看的待处理报销单？

假如我登录的是员工账号，那是哪一段语句控制只显示给员工看的待处理报销单？

package com.imooc.oa.biz.Impl;

import com.imooc.oa.biz.ClaimVoucherBiz;
import com.imooc.oa.dao.ClaimVoucherDao;
import com.imooc.oa.dao.ClaimVoucherItemDao;
import com.imooc.oa.dao.DealRecordDao;
import com.imooc.oa.dao.EmployeeDao;
import com.imooc.oa.entity.ClaimVoucher;
import com.imooc.oa.entity.ClaimVoucherItem;
import com.imooc.oa.entity.DealRecord;
import com.imooc.oa.entity.Employee;
import com.imooc.oa.global.Contant;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.Date;
import java.util.List;

@Service("claimVoucherBiz")
public class ClaimVoucherBizImpl implements ClaimVoucherBiz {
    @Autowired
    private ClaimVoucherDao claimVoucherDao;
    @Autowired
    private ClaimVoucherItemDao claimVoucherItemDao;
    @Autowired
    private DealRecordDao dealRecordDao;
    @Autowired
    private EmployeeDao employeeDao;

    public void save(ClaimVoucher claimVoucher, List<ClaimVoucherItem> items) {
        claimVoucher.setCreateTime(new Date());
        claimVoucher.setNextDealSn(claimVoucher.getCreateSn());
        claimVoucher.setStatus(Contant.CLAIMVOUCHER_CREATED);
        claimVoucherDao.insert(claimVoucher);
        for (ClaimVoucherItem item : items) {
            item.setClaimVoucherId(claimVoucher.getId());//不明白
            claimVoucherItemDao.insert(item);
        }
    }

    public ClaimVoucher get(int id) {
        return claimVoucherDao.select(id);
    }

    public List<ClaimVoucherItem> getItems(int cvid) {
        return claimVoucherItemDao.selectByClaimVoucher(cvid);
    }

    public List<DealRecord> getRecords(int cvid) {
        return dealRecordDao.selectByClaimVoucher(cvid);
    }

    public List<ClaimVoucher> getforSelf(String sn) {
        return claimVoucherDao.selectByCreateSn(sn);
    }

    public List<ClaimVoucher> getforDeal(String sn) {
        return claimVoucherDao.selectByNextDealSn(sn);
    }

    public void update(ClaimVoucher claimVoucher, List<ClaimVoucherItem> items) {

        claimVoucher.setNextDealSn(claimVoucher.getCreateSn());
        claimVoucher.setStatus(Contant.CLAIMVOUCHER_CREATED);
        claimVoucherDao.update(claimVoucher);

        List<ClaimVoucherItem> olds = claimVoucherItemDao.selectByClaimVoucher(claimVoucher.getId());
        for (ClaimVoucherItem old : olds) {
            boolean isHave = false;
            for (ClaimVoucherItem item : items) {
                if (item.getId() == old.getId()) {
                    isHave = true;
                    break;
                }
            }
            //这里看不懂
            if (!isHave) {
                claimVoucherItemDao.delete(old.getId());
            }
        }
        for (ClaimVoucherItem item : items) {
            //不理解
            item.setClaimVoucherId(claimVoucher.getId());
            if (item.getId() != null && item.getId() > 0) {
                claimVoucherItemDao.update(item);
            } else {
                claimVoucherItemDao.insert(item);
            }
        }
    }


    public void submit(int id) {
        ClaimVoucher claimVoucher = claimVoucherDao.select(id);
        Employee employee = employeeDao.select(claimVoucher.getCreateSn());

        claimVoucher.setStatus(Contant.CLAIMVOUCHER_SUBMIT);

        claimVoucher.setNextDealSn(employeeDao.selectByDepartmentAndPost(employee.getDepartmentSn(), Contant.POST_FM).get(0).getSn());
        claimVoucherDao.update(claimVoucher);

        DealRecord dealRecord = new DealRecord();
        dealRecord.setDealWay(Contant.DEAL_SUBMIT);
        dealRecord.setDealSn(employee.getSn());
        dealRecord.setClaimVoucherId(id);
        dealRecord.setDealResult(Contant.CLAIMVOUCHER_SUBMIT);
        dealRecord.setDealTime(new Date());
        dealRecord.setComment("无");
        dealRecordDao.insert(dealRecord);
    }
}

package com.imooc.oa.controller;


import com.imooc.oa.biz.ClaimVoucherBiz;
import com.imooc.oa.dto.ClaimVoucherInfo;
import com.imooc.oa.entity.Employee;
import com.imooc.oa.global.Contant;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpSession;
import java.util.Map;

@Controller("claimVoucherController")
@RequestMapping("/claim_voucher")
public class ClaimVoucherController {
    @Autowired
    private ClaimVoucherBiz claimVoucherBiz;

    @RequestMapping("/to_add")
    public String toAdd(Map<String, Object> map) {
        map.put("items", Contant.getItems());
        map.put("info", new ClaimVoucherInfo());
        return "claim_voucher_add";
    }

    @RequestMapping("/add")
    public String add(HttpSession session, ClaimVoucherInfo info) {
        Employee employee = (Employee) session.getAttribute("employee");
        info.getClaimVoucher().setCreateSn(employee.getSn());
        claimVoucherBiz.save(info.getClaimVoucher(), info.getItems());
        return "redirect:detail?id=" + info.getClaimVoucher().getId();
    }

    //为什么链接的id跟这个方法对应？
    @RequestMapping("/detail")
    public String detail(int id, Map<String, Object> map) {
        map.put("claimVoucher", claimVoucherBiz.get(id));
        map.put("items", claimVoucherBiz.getItems(id));
        map.put("records", claimVoucherBiz.getRecords(id));
        return "claim_voucher_detail";
    }

    @RequestMapping("/self")
    public String self(HttpSession session, Map<String, Object> map) {
        Employee employee = (Employee) session.getAttribute("employee");
        map.put("list", claimVoucherBiz.getforSelf(employee.getSn()));

        return "claim_voucher_self";
    }

    @RequestMapping("/deal")
    public String deal(HttpSession session, Map<String, Object> map) {
        Employee employee = (Employee) session.getAttribute("employee");
        map.put("list", claimVoucherBiz.getforDeal(employee.getSn()));

        return "claim_voucher_deal";
    }

    @RequestMapping("/to_update")
    public String toUpdate(int id, Map<String, Object> map) {
        map.put("items", Contant.getItems());
        ClaimVoucherInfo info = new ClaimVoucherInfo();
        info.setClaimVoucher(claimVoucherBiz.get(id));
        info.setItems(claimVoucherBiz.getItems(id));

        map.put("info", info);
        return "claim_voucher_update";
    }

    @RequestMapping("/update")
    public String update(HttpSession session, ClaimVoucherInfo info) {
        Employee employee = (Employee) session.getAttribute("employee");
        info.getClaimVoucher().setCreateSn(employee.getSn());
        claimVoucherBiz.update(info.getClaimVoucher(), info.getItems());
        return "redirect:deal";
    }

    @RequestMapping("/submit")
    public String submit(int id) {
        claimVoucherBiz.submit(id);
        return "redirect:deal";
    }

}

是哪段代码做了判断呢？