我有以下内容将返回数据库中的 100k 行,这应该会为我找到 6 个随机值。问题是在 Lotto 中你不能有多个相同的值。我注意到有些值显示相同,例如..
21-21-34-3-14-46
很明显,21
和 21
不是 Lotto 彩票中的有效数字。所以我的问题是如何在生成随机值时检查没有数字相同?
这是我的代码:
SET NOCOUNT ON
DECLARE @intFlag INT
SET @intFlag = 1
WHILE (@intFlag <=500000)
BEGIN
--Do Stuff
DECLARE @Random1 INT, @Random2 INT, @Random3 INT, @Random4 INT, @Random5 INT, @Random6 INT, @Upper INT, @Lower INT
---- This will create a random number between 1 and 49
SET @Lower = 1 ---- The lowest random number
SET @Upper = 49 ---- The highest random number
SELECT @Random1 = ROUND(((@Upper - @Lower -1) * RAND() + @Lower), 0)
SELECT @Random2 = ROUND(((@Upper - @Lower -1) * RAND() + @Lower), 0)
SELECT @Random3 = ROUND(((@Upper - @Lower -1) * RAND() + @Lower), 0)
SELECT @Random4 = ROUND(((@Upper - @Lower -1) * RAND() + @Lower), 0)
SELECT @Random5 = ROUND(((@Upper - @Lower -1) * RAND() + @Lower), 0)
SELECT @Random6 = ROUND(((@Upper - @Lower -1) * RAND() + @Lower), 0)
--SELECT @Random;
INSERT INTO CustomerSelections
([draw_date]
,[val1]
,[val2]
,[val3]
,[val4]
,[val5]
,[val6])
VALUES
(
'2013-07-05'
,@Random1
,@Random2
,@Random3
,@Random4
,@Random5
,@Random6
)
SET @intFlag = @intFlag + 1
END
GO
@戈登:
最佳答案
当我想到没有重复的随机数时,我想到的是“排列”。因此,我们的想法是生成一组可能的值,对它们进行随机排序,然后选择前六个值作为您的集合:
with nums as (
select @lower as n
union all
select nums.n+1
from nums
where nums.n < @upper
),
randnums as
(select nums.n, ROW_NUMBER() over (order by newid()) as seqnum
from nums
)
select @random1 = MAX(case when rn.seqnum = 1 then rn.n end),
@random2 = MAX(case when rn.seqnum = 2 then rn.n end),
@random3 = MAX(case when rn.seqnum = 3 then rn.n end),
@random4 = MAX(case when rn.seqnum = 4 then rn.n end),
@random5 = MAX(case when rn.seqnum = 5 then rn.n end),
@random6 = MAX(case when rn.seqnum = 6 then rn.n end)
from randnums rn;
关于sql - 使用 SQL 确保随机数不相同,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17435905/