SQL优化
select b.fno 航班号, b.fdest 目的站, b.DEPTIME 起飞时间, b.weight 总载量, isnull(sum(a.weight), 0) 总订舱量, b.weight - isnull(sum(a.weight), 0) 剩余量, isnull(dbo.getbookingd(b.fno, b.fdep, b.fdest, b.fdate, 'CANYYB'), 0) as CANYYB, isnull(dbo.getbookingd(b.fno, b.fdep, b.fdest, b.fdate, 'CKGSZX'), 0) as CKGSZX, isnull(dbo.getbookingd(b.fno, b.fdep, b.fdest, b.fdate, 'SHEHYB'), 0) as SHEHYB, isnull(dbo.getbookingd(b.fno, b.fdep, b.f