在 SQL (Sybase Server IQ) 中选择随机子集 [英] Selecting a Random Subset in SQL (Sybase Server IQ)

问题描述

我正在尝试使用 rand() 或 newid() 选择记录的随机子集，但每次运行以下命令时，我总是得到相同的结果:

I'm trying to select a random subset of records using either rand() or newid(), but any time I run the following, I always get the same results back:

SELECT *,rand() as rid
INTO #mytable
FROM othertable

select top 10 * from #mytable order by rid

我已经尝试了所有的变体，但是当我像上面那样做时，sybase server iq 似乎总是返回相同的 rand() 值.当我尝试做

I've tried every variation of this, but it seems that sybase server iq always returns the same rand() value when I do it like the above. When I try to do

SELECT * FROM othertable order by newid()

我收到一条错误消息，说在 order by 中使用 newid() 是非法的.

I get an error saying it's illegal to use newid() in the order by.

有什么建议吗?

推荐答案

在 Sybase T-SQL 中，NEWID() 系统函数生成人类可读的全局唯一 ID.在目标表上发出 SELECT 语句时，在 ORDER BY 子句中包含 NEWID() 系统函数.

In Sybase T-SQL, The NEWID() system function generates human-readable, globally unique IDs. Include the NEWID() system function in the ORDER BY clause when issuing the SELECT statement on the target table.

用法:

SELECT top 10 id from TABLE order by NEWID();

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