生成n位随机字符串

--1、借助newid()

Go

--创建视图(因为在函数中无法直接使用newid())

create view vnewid

as

select newid() N'MacoId';

go

--创建函数

create function getrandstr(@n int)

returns varchar(max)

as

begin

declare @i int

set @i=ceiling(@n/32.00)

declare @j int

set @j=0

declare @k varchar(max)

set @k=''

while @j<@i

begin

select @k=@k+replace(cast(MacoId as varchar(36)),'-','') from vnewid

set @j=@j+1

end

set @k=substring(@k,1,@n)

return @k

end

--测试示例

select dbo.getrandstr(75)

--运行结果

/*

D185504AD09C4D5796F7016983E67414CEE25162EA9F43D195D43328A4CF01AC7C586521D8E

*/

--我们可以发现结果中的字母都是大写的，或是都是小写的。

--换种方法来写下：

go

--创建函数

create function [dbo].[m_rand](@mycount int)

returns nvarchar(2000)

as

begin

declare @maco_wang table (id varchar(1))

declare @maco_number int,@number int;

declare @my_one nvarchar(max),@my_two nvarchar(max)

set @my_one='';set @maco_number=0; set @number =48;

while (@number>=48 and @number<=57) or (@number>=65 and @number<=90) or (@number>=97 and @number<=122)

begin

insert into @maco_wang select char(@number)

set @number=@number+1;

if(@number=58)

begin

set @number=65

end

if(@number=91)

begin

set @number=97

end

end

while @maco_number<@mycount

begin

select @my_two=id from @maco_wang

order by (select MacoId from dbo.m_macoview);

set @my_one=@my_two+@my_one;

set @maco_number=@maco_number+1;

end

return @my_one

end

--测试用例

select [dbo].[m_rand](75)

--运行结果

/*

5nN0w4o4VOkjacB5so2uvCuw2ZRrnBhxEi4IcsEOHzBbStKmR1p8ASH4N4XaxhDoDEtkX8bZ0CR

*/