判断修改时候判断用户名不能与数据库数据相同,但现在修改用户名数据库中有但可修改

String id = ParamUtils.getString(request, "id", "");

String school_name = ParamUtils.getString(request, "school_name", "");
    schoolPo.setId(null);
    schoolPo.setSchool_name(school_name);
    list = souSchoolService.querySourceSchoolName(schoolPo);
    if(list.size() == 0 || list==null){
     pageInfo.setId(new BigDecimal(id));
     souSchoolService.updateSourceSchool(pageInfo);
     result=2;     
    }else{
     schoolPo.setId(new BigDecimal(id));
     schoolPo.setSchool_name(null);
     list = souSchoolService.querySourceSchoolName(schoolPo);
     if(list.size() == 0 || list==null){
      pageInfo.setId(new BigDecimal(id));
      souSchoolService.updateSourceSchool(pageInfo);
      result=2;
     }else if(list.get(0).getSchool_name().equals(school_name)){
      pageInfo.setId(new BigDecimal(id));
      souSchoolService.updateSourceSchool(pageInfo);
      result=2;
     }else{
      result=5;
     }
     
    }