Creating a GUID. 100% unique ID

Here are 2 ways to create a UID...
The 1st one produces a format that is equal to that of SQL Servers UID's.

VB Code:

Option Explicit
 
Private Declare Function CoCreateGuid Lib "ole32" (id As Any) As Long
Private Declare Function GetTickCount Lib "kernel32" () As Long
 
Private Sub Form_Load()
Dim strOld      As String
Dim strNew      As String
Dim intIndex    As Long
Dim lngStart    As Long
    lngStart = GetTickCount
    For intIndex = 1 To 10000
        strNew = CreateUID
        If strNew = strOld Then
            MsgBox "No unique! Boooooooo", vbCritical
        End If
        strOld = strNew
    Next intIndex
    MsgBox GetTickCount - lngStart & "ms", vbInformation
End Sub
 
Private Function CreateUID() As String
Dim bytID(1 To 16)      As Byte
Dim intIndex            As Integer
Dim strUID              As String
    Call CoCreateGuid(bytID(1))
    For intIndex = 1 To 16
        If bytID(intIndex) < CByte(16) Then
            strUID = strUID & "0"
        End If
        strUID = strUID & Hex$(bytID(intIndex))
        Select Case intIndex
            Case 4, 6, 8, 10
                strUID = strUID & "-"
        End Select
    Next intIndex
    CreateUID = strUID
End Function

And the 2nd way...

VB Code:

Option Explicit
 
Private Declare Function CoCreateGuid Lib "ole32" (id As Any) As Long
Private Declare Function GetTickCount Lib "kernel32" () As Long
 
Private Type mtypUID
    Data1 As Long
    Data2 As Integer
    Data3 As Integer
    Data4(7) As Byte
End Type
 
Private Sub Form_Load()
Dim strOld      As String
Dim strNew      As String
Dim intIndex    As Long
Dim lngStart    As Long
    lngStart = GetTickCount
    For intIndex = 1 To 10000
        strNew = CreateGUID
        If strNew = strOld Then
            MsgBox "No unique! Boooooooo", vbCritical
        End If
        strOld = strNew
    Next intIndex
    MsgBox GetTickCount - lngStart & "ms", vbInformation
End Sub
 
Private Function CreateGUID() As String
Dim udtGUID As mtypUID
    Call CoCreateGuid(udtGUID)
    CreateGUID = _
        String(8 - Len(Hex$(udtGUID.Data1)), "0") & Hex$(udtGUID.Data1) & _
        String(4 - Len(Hex$(udtGUID.Data2)), "0") & Hex$(udtGUID.Data2) & _
        String(4 - Len(Hex$(udtGUID.Data3)), "0") & Hex$(udtGUID.Data3) & _
        IIf((udtGUID.Data4(0) < &H10), "0", "") & Hex$(udtGUID.Data4(0)) & _
        IIf((udtGUID.Data4(1) < &H10), "0", "") & Hex$(udtGUID.Data4(1)) & _
        IIf((udtGUID.Data4(2) < &H10), "0", "") & Hex$(udtGUID.Data4(2)) & _
        IIf((udtGUID.Data4(3) < &H10), "0", "") & Hex$(udtGUID.Data4(3)) & _
        IIf((udtGUID.Data4(4) < &H10), "0", "") & Hex$(udtGUID.Data4(4)) & _
        IIf((udtGUID.Data4(5) < &H10), "0", "") & Hex$(udtGUID.Data4(5)) & _
        IIf((udtGUID.Data4(6) < &H10), "0", "") & Hex$(udtGUID.Data4(6)) & _
        IIf((udtGUID.Data4(7) < &H10), "0", "") & Hex$(udtGUID.Data4(7))
End Function

They both create a UID, however, the 1st chunk of code is twice as fast...

Hope this is useful to someone...

Woka