mybatisplusin方法使用说明

//查询到list集合
List userList = userService.selectById(id);
//结果集
List resultList = new ArrayList<>();
//遍历集合取值
 userList .forEach(item->{
   resultList.add(item.getYouNeedId());
 });
 //条件构造器in上手使用
 QueryWrapper qw = new QueryWrapper<>();
 qw.in("you_need_id", resultList);
 //这里有个分页的查询，你也可以不用分页，用mybatisplus里面封装的其他方法
 IPage userIPage = userMapper.selectPage(page, qw);
 //返回查询结果，getRecords也是mybatisplus里面封装的方法
 return contractRecordIPage.getRecords();

//要查的参数
String masterIds = "81554,5654,55948,48945";

QueryWrapper pauperqw = new QueryWrapper<>();
pauperqw.in("user_id",masterIds);
UserInfoService.list(pauperqw);

==> Preparing:SELECT user_id,user_name,update_job_dt,group_name,create_dt,create_by,
update_dt,update_by FROM fpjy_pauper_info WHERE (user_id IN (&＃63;)) 
==> Parameters: 81554,5654,55948,48945(String)
<==   Total: 0

==> Preparing:SELECT * FROM fpjy_pauper_info WHERE (user_id IN (81554,5654,55948,48945)) 
==> Parameters: 
<==   Total: 4