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Create GUIDs by using Active Server Pages in IIS

  • Articol

This article provides information about how to create several example pages by using various forms of GUIDs for Active Server Pages (ASP) pages to use. These values can be used to create unique data entries in a database, or anywhere else where a unique data field is required.

Original product version:   Internet Information Services
Original KB number:   320375

Note

Because these examples don't use session variables, these examples also work on Web servers that have session state disabled.

Create a simple time-based GUID

This example creates a simple 14-character time-based GUID by using the current year, month, day, hour, minute, and seconds. This permits you to sort data based on the GUID.

  1. Select Start, point to Programs, select Accessories, and then select Notepad to open Notepad.

  2. Type or paste the following ASP code in Notepad:

    <%@LANGUAGE="VBSCRIPT"%>
<HTML>
    <BODY>
        <%
            Response.Write "GUID = " & CreateGUID()

            Function CreateGUID()
                Dim tmpTemp
                tmpTemp = Right(String(4,48) & Year(Now()),4)
                tmpTemp = tmpTemp & Right(String(4,48) & Month(Now()),2)
                tmpTemp = tmpTemp & Right(String(4,48) & Day(Now()),2)
                tmpTemp = tmpTemp & Right(String(4,48) & Hour(Now()),2)
                tmpTemp = tmpTemp & Right(String(4,48) & Minute(Now()),2)
                tmpTemp = tmpTemp & Right(String(4,48) & Second(Now()),2)
                CreateGUID = tmpTemp
            End Function
        %>
    </BODY>
</HTML>

  3. Save the page:

    1. On the File menu, select Save.
    2. Locate the root folder for your Web site, which is typically the C:\InetPub\Wwwroot folder for the default Web site.
    3. Name the file GuidTest0.asp.
    4. Select Save.
    5. On the File menu, select Exit.

  4. Locate the page with Internet Explorer. You see a GUID. As you refresh the page, you see the GUID increment.

Create a simple time-offset GUID

This example creates a 20-character time-based GUID by using the offset in seconds from 12:00 midnight on January 1, 2000. This permits you to sort data based on the GUID, and can be updated to use any other date as the base.

  1. Select Start, point to Programs, select Accessories, and then select Notepad to open Notepad.

  2. Type or paste the following ASP code in Notepad:

    <%@LANGUAGE="VBSCRIPT"%>
<HTML>
    <BODY>
        <%
            Response.Write "GUID = " & CreateGUID()

            Function CreateGUID()
                Dim tmpTemp1,tmpTemp2
                tmpTemp1 = Right(String(15,48) & CStr(CLng(DateDiff("s","1/1/2000",Date()))), 15)
                tmpTemp2 = Right(String(5,48) & CStr(CLng(DateDiff("s","12:00:00 AM",Time()))), 5)
                CreateGUID = tmpTemp1 & tmpTemp2
            End Function
        %>
    </BODY>
</HTML>

  3. Save the page:

    1. On the File menu, select Save.
    2. Locate the root folder for your Web site, which is typically the C:\InetPub\Wwwroot folder for the default Web site.
    3. Name the file GuidTest1.asp.
    4. Select Save.
    5. On the File menu, select Exit.

  4. Locate the page with Internet Explorer. You see a GUID. As you refresh the page, you see the GUID increment.

Note

This example permits uniqueness only when the function is not called two times in the same second. Any two calls to the function at the same second cause a collision. This may not cause a problem depending on how your code is using the function, but you can use the Create a more unique time-offset GUID example to allow unique values that occur in the same second.

Create a more unique time-offset GUID

This example, like the Create a simple time-offset GUID example, creates a time-based GUID, but it is 25 characters long. This example creates a 20-character value from the offset in seconds from 12:00 midnight on January 1, 2000, and appends an additional five random numbers to the end of that. This permits you to sort data based on the GUID, but permits much greater uniqueness. This can be updated to use any other date as the base.

  1. Select Start, point to Programs, select Accessories, and then select Notepad to open Notepad.

  2. Type or paste the following ASP code in Notepad:

    <%@LANGUAGE="VBSCRIPT"%>
<HTML>
    <BODY>
        <%
            Response.Write "GUID = " & CreateGUID()

            Function CreateGUID()
                Randomize Timer
                Dim tmpTemp1,tmpTemp2,tmpTemp3
                tmpTemp1 = Right(String(15,48) & CStr(CLng(DateDiff("s","1/1/2000",Date()))), 15)
                tmpTemp2 = Right(String(5,48) & CStr(CLng(DateDiff("s","12:00:00 AM",Time()))), 5)
                tmpTemp3 = Right(String(5,48) & CStr(Int(Rnd(1) * 100000)),5)
                CreateGUID = tmpTemp1 & tmpTemp2 & tmpTemp3
            End Function
        %>
    </BODY>
</HTML>

  3. Save the page:

    1. On the File menu, select Save.
    2. Locate the root folder for your Web site, which is typically the C:\InetPub\Wwwroot folder for the default Web site.
    3. Name the file GuidTest2.asp.
    4. Select Save.
    5. On the File menu, select Exit.

  4. Locate the page with Internet Explorer. You see a GUID. As you refresh the page, you see the first 20 characters of the GUID increment, and the last five characters are random.

Note

This example and the Create a simple time-offset GUID example are created for time-based serialization of calls to the CreateGUID function. If sorting data based on time is not a requirement, you can use the Create a simple random GUID example to create a random GUID.

Create a simple random GUID

  1. Select Start, point to Programs, select Accessories, and then select Notepad to open Notepad.

  2. Type or paste the following ASP code in Notepad:

    <%@LANGUAGE="VBSCRIPT"%>
<HTML>
    <BODY>
        <%
            Response.Write "GUID = " & CreateGUID()

            Function CreateGUID()
                Randomize Timer
                Dim tmpCounter,tmpGUID
                Const strValid = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                For tmpCounter = 1 To 20
                tmpGUID = tmpGUID & Mid(strValid, Int(Rnd(1) * Len(strValid)) + 1, 1)
                Next
                CreateGUID = tmpGUID
            End Function
        %>
    </BODY>
</HTML>

  3. Save the page:

    1. On the File menu, select Save.
    2. Locate the root folder for your Web site, which is typically the C:\InetPub\Wwwroot folder for the default Web site.
    3. Name the file GuidTest3.asp.
    4. Select Save.
    5. On the File menu, select Exit.

  4. Locate the page with Internet Explorer. You see a 20-character random GUID. As you refresh the page, you see the value change randomly.

Note

This example creates a fixed-length random GUID. To create a variable-length GUID, use the Create a variable-length random GUID example.

Create a variable-length random GUID

  1. Select Start, point to Programs, select Accessories, and then select Notepad to open Notepad.

  2. Type or paste the following ASP code in Notepad:

    <%@LANGUAGE="VBSCRIPT"%>
<HTML>
    <BODY>
        <%
            Response.Write "<P>GUID = " & CreateGUID(10)
            Response.Write "<P>GUID = " & CreateGUID(25)
            Response.Write "<P>GUID = " & CreateGUID(50)

            Function CreateGUID(tmpLength)
                Randomize Timer
                Dim tmpCounter,tmpGUID
                Const strValid = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                For tmpCounter = 1 To tmpLength
                tmpGUID = tmpGUID & Mid(strValid, Int(Rnd(1) * Len(strValid)) + 1, 1)
                Next
                CreateGUID = tmpGUID
            End Function
        %>
</BODY>
</HTML>

  3. Save the page:

    1. On the File menu, select Save.
    2. Locate the root folder for your Web site, which is typically the C:\InetPub\Wwwroot folder for the default Web site.
    3. Name the file GuidTest4.asp.
    4. Select Save.
    5. On the File menu, select Exit.

  4. Locate the page with Internet Explorer. You see a 10-character, 25-character, and 50-character random GUID. As you refresh the page, you see the values change randomly.

Note

This example and the Create a simple random GUID example both create strings of concatenated random characters. The Create a windows-style random GUID example expands on this functionality to create a GUID that is formatted like a Windows GUID.

Create a windows-style random GUID

Windows primarily uses GUIDs when it registers Class IDs for components and other objects, but GUIDs can be used for anything. Windows GUIDs are long strings of formatted hexadecimal characters, meaning that they use the numbers 0 through 9 and the letters A through F. (Microsoft Access also has a built-in Replication ID in the same format.) This example shows how to use code that is similar to the Create a variable-length random GUID example code to create a GUID like a Windows GUID.

  1. Select Start, point to Programs, select Accessories, and then select Notepad to open Notepad.

  2. Type or paste the following ASP code in Notepad:

    <%@LANGUAGE="VBSCRIPT"%>
<HTML>
    <BODY>
        <%
            Response.Write "<P>GUID = " & CreateWindowsGUID()

            Function CreateWindowsGUID()
                CreateWindowsGUID = CreateGUID(8) & "-" & _
                CreateGUID(4) & "-" & _
                CreateGUID(4) & "-" & _
                CreateGUID(4) & "-" & _
                CreateGUID(12)
            End Function

            Function CreateGUID(tmpLength)
                Randomize Timer
                Dim tmpCounter,tmpGUID
                Const strValid = "0123456789ABCDEF"
                For tmpCounter = 1 To tmpLength
                tmpGUID = tmpGUID & Mid(strValid, Int(Rnd(1) * Len(strValid)) + 1, 1)
                Next
                CreateGUID = tmpGUID
            End Function
        %>
    </BODY>
</HTML>

  3. Save the page:

    1. On the File menu, select Save.
    2. Locate the root folder for your Web site, which is typically the C:\InetPub\Wwwroot folder for the default Web site.
    3. Name the file GuidTest5.asp.
    4. Select Save.
    5. On the File menu, select Exit.

  4. Locate the page with Internet Explorer. You see a random GUID that is formatted like a Windows GUID. As you refresh the page, you see the value change randomly.

Create a stronger windows-style random GUID

Because Windows GUIDs use hexadecimal numbers for each character, 16 values are possible per character in the GUID. If you expand the values to include the whole alphabet, 36 values are possible per character in the GUID. This example uses the function from the Create a variable-length random GUID example to create a GUID in the same format as a Windows GUID.

  1. Select Start, point to Programs, select Accessories, and then select Notepad to open Notepad.

  2. Type or paste the following ASP code in Notepad:

    <%@LANGUAGE="VBSCRIPT"%>
<HTML>
    <BODY>
        <%
            Response.Write "<P>GUID = " & CreateWindowsGUID()

            Function CreateWindowsGUID()
                CreateWindowsGUID = CreateGUID(8) & "-" & _
                CreateGUID(4) & "-" & _
                CreateGUID(4) & "-" & _
                CreateGUID(4) & "-" & _
                CreateGUID(12)
            End Function

            Function CreateGUID(tmpLength)
                Randomize Timer
                Dim tmpCounter,tmpGUID
                Const strValid = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                For tmpCounter = 1 To tmpLength
                tmpGUID = tmpGUID & Mid(strValid, Int(Rnd(1) * Len(strValid)) + 1, 1)
                Next
                CreateGUID = tmpGUID
            End Function
        %>
    </BODY>
</HTML>

  3. Save the page:

    1. On the File menu, select Save.
    2. Locate the root folder for your Web site, which is typically the C:\InetPub\Wwwroot folder for the default Web site.
    3. Name the file GuidTest6.asp.
    4. Select Save.
    5. On the File menu, select Exit.

  4. Locate the page with Internet Explorer. You see a random GUID that is formatted like a Windows GUID. As you refresh the page, you see the value change randomly.