如何生成一串16位唯一数字?急...

[sqlaqandy]

RT

[思危]

要想真的唯一16是不够，用GUID

[sqlaqandy]

问题是只能用16位,让这16保持十几年就可以了

[m_dbsky]

十几年?

[zsj1101]

给楼主一段代码研究一下
利用GUID防止重复隨机數的出現

　
Private Type GUID
Data1 As Long
Data2 As Long
Data3 As Long
Data4(8) As Byte
End Type
Private Declare Function CoCreateGuid Lib "ole32.dll" (pguid As GUID) As Long
Private Declare Function StringFromGUID2 Lib "ole32.dll" (rguid As Any, ByVal _
lpstrClsId As Long, _
ByVal cbMax As Long) As Long
Private Function GUIDGen() As String
Dim uGUID As GUID
Dim sGUID As String
Dim bGUID() As Byte
Dim lLen As Long
Dim RetVal As Long
lLen = 40
bGUID = String(lLen, 0)
CoCreateGuid uGUID '把結构轉換成一個可顯示的字符串
RetVal = StringFromGUID2(uGUID, VarPtr(bGUID(0)), lLen)
sGUID = bGUID
If (Asc(Mid$(sGUID, RetVal, 1)) = 0) Then
RetVal = RetVal - 1
GUIDGen = Left$(sGUID, RetVal)
End If
End Function

[roscoe]

这个好象取决于你的记录数吧,
其实可以用个笨方法,建张表,
设一字符型字段16字长的. 并为主关键字段.
然后你生成随机数,往表中INSERT,成功肯定是唯一的,失败就是不唯一的.

[王晓华-吹泡泡的小猫]

coCreateGuid

[DentistryDoctor]

Yes, GUID!

[kencharles]

好像很多注册码就是这么生成的吧！

[CW_Wei]

up

[思危]

用 年的后2位 + 2位月 + 2位日+ 2位时 + 2位分 + 2位秒 + 4位1-9999 生成一个16的ID ，除非你没秒生成10000个ID，否则 99年才有可能重复

[思危]

我有一个程序就是这么生成的ID