累計占比

 1 CREATE TABLE #t1(
 2        PlantNo    varchar(4),
 3        vendorCode varchar(10),
 4        amount decimal(18,2))
 5        
 6 insert #t1 values('P112','1',10)
 7 insert #t1 values('P112','2',20)
 8 insert #t1 values('P112','3',30)
 9 insert #t1 values('P112','4',40)
10 insert #t1 values('P115','1',10)
11 
12 select #t1.plantno,vendorCode,amount,amount as amountTotal,amount  as amountTotal2,amount as rate
13   into #t2
14 from #t1 order by plantNo,amount desc
15 
16 update #t2 set amountTotal=(select SUM(amount) from #t1 where #t1.PlantNo=#t2.PlantNo)
17 update #t2 set amountTotal2=(select SUM(amount) from #t1 where #t1.PlantNo=#t2.PlantNo and amount>=#t2.amount)
18 update #t2 set rate=amountTotal2/amountTotal
19 select * from #t2
20 drop table #t1
21 drop table #t2
22 
23 --結果
24 plantno    vendorCode    amount    amountTotal    amountTotal2    rate
25 P112    4    40.00    100.00    40.00    0.40
26 P112    3    30.00    100.00    70.00    0.70
27 P112    2    20.00    100.00    90.00    0.90
28 P112    1    10.00    100.00    100.00    1.00
29 P115    1    10.00    10.00    10.00    1.00

這部分程序的作用是統計前幾大累計的佔比問題。比如:最富的那個人占了2%,第二的人占了1.5%，那麼前2個人累計占比3.5%。