可能重复:
Simple update statement so that all rows are assigned a different value
有没有办法从子查询中选择一个随机值(如颜色)?这是我尝试过但在每次运行中得到相同的值:
SELECT TOP (100) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS ID,--Sequential number from 1 to ..
(SELECT TOP 1 color
FROM ( VALUES (0, 'Red'),
(1, 'Green'),
(2, 'Yellow') ) colors(id, color)
ORDER BY NEWID() ) AS RandomColor
FROM sys.all_columns ac1
CROSS JOIN sys.all_columns ac2
但如果我单独运行这件作品,我会得到不同的颜色:
SELECT TOP 1 color
FROM ( VALUES (0, 'Red'),
(1, 'Green'),
(2, 'Yellow') ) colors(id, color)
ORDER BY NEWID()
答案 0 :(得分:3)
这样的事可能
select ac1.ID, r.color from
(SELECT TOP (100)
-- changed because it didn't work in mssql 2012
--ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) as ID,
ROW_NUMBER() OVER (ORDER BY newid()) as ID,
ROW_NUMBER() OVER (ORDER BY newid()) as dummy
FROM sys.all_columns
order by id
) ac1
cross apply
(SELECT top 1 color FROM ( VALUES (0,'Red'),(1,'Green'),(2,'Yellow') ) colors(id,color)
where id = dummy % 3
) r