$fangtai_arr = db("t_wxroomstatus")->field("F_RoomType,count(*) as RoomNum,sum(case when F_RoomStatus='入住' then 0 else 1 end) as KongRoomNum,sum(case when F_RoomStatus='入住' then 1 else 0 end) as InRoomNum") ->where('F_Comkey',30000825) ->group("F_RoomType") ->select();

这里的查询数据，case when 函数，条件用到中文“入住”，会乱码，查询也会有问题，这该怎么解决