Question

如何在SQL Server 2008中编写存储过程，在整数数据类型的两列中生成300万随机数。

Answer 1

SELECT TOP 3000000 
    ABS(CHECKSUM(NewId())) As RndCol1, 
    ABS(CHECKSUM(NewId())) AS RndCol2
FROM 
    sys.objects s1 
    CROSS JOIN sys.objects s2 
    CROSS JOIN sys.objects s3
    CROSS JOIN sys.objects s4

[您可能需要使用卡方检验来检查这些数字的实际分布]

更新：这些随机性可能不符合卡方分布测试。我建议您根据自己的情况进行测试。

Answer 2

您可以使用CTE，例如：

create procedure dbo.GiveMeRandomNumbers
as
    begin
    with qry as (
        select  CAST(CAST(NEWID() AS VARBINARY) AS INT) as col1
        ,       CAST(CAST(NEWID() AS VARBINARY) AS INT) as col2
        ,       0 as i
        union all
        select  CAST(CAST(NEWID() AS VARBINARY) AS INT) as col1
        ,       CAST(CAST(NEWID() AS VARBINARY) AS INT) as col2
        ,       i + 1 
        from    qry
        where   i < 3000000
    )
    select  col1, col2
    from    qry
    option  (maxrecursion 0)
    end

这使用newid，因为rnd函数将为CTE的每个递归应用返回相同的结果。

如何在SQL Server 2008中编写存储过程，生成300万随机编号

2 个答案: