sql

[此贴子已经被作者于2016-5-24 19:51编辑过]

你是要判断还是要生成？
1、判断
用SUBSTRING()，ISNUMERIC(),CHAR()函数来判断

生成

declare @s char(5)
declare @r int
declare @i int

set @s='A1012'
if (ascii(substring(@s,1,1))>=65 and ascii(substring(@s,1,1))<=90) or
   (ascii(substring(@s,1,1))>=97 and ascii(substring(@s,1,1))<=122)
    set @r=1
else
    set @r=0

set @i=2
while @i<=5
begin
     if ascii(substring(@s,@i,1))>=48 and ascii(substring(@s,@i,1))<=57
        set @r=@r*1
     else
        set @r=@r*0
     set @i=@i+1
end

if @r>0
select 'the string is ok'
else
select 'the string is not ok'

随机生成？

是的

好长啊，我看不懂