select uv.room_id, room_name, count(distinct user_id) user_count from user_view_tb uv join room_info_tb rit on uv.room_id = rit.room_id where out_time <= '23:59:59' and out_time >= '23:00:00' group by uv.room_id, room_name order by user_count desc
只需统计退出时间(out_time)在晚上11-12点之间的人次--在线,就行(需去重)