我对第四个查询作一些修改:select cruise_nm,cruise.cruise_cd,convert(char(2),convert(float,seats_avail)/convert(float,tot_seats)*100)+''%'' as ''空闲率''
from cruise_book inner join cruise on cruise_book.cruise_cd=cruise.cruise_cd
where (tot_seats-seats_avail)=(select min(tot_seats-seats_avail) from cruise_book)