ACC: How to Sort Records in Case-Sensitive ( ASCII) Order

• Microsoft Access versions 1.0, 1.1, 2.0, 7.0, 97

SUMMARY

Moderate: Requires basic macro, coding, and interoperability skills.

This article shows you how to create a sample user-defined function to sort records in case-sensitive (or ASCII) order.

This article assumes that you are familiar with Visual Basic for Applications and with creating Microsoft Access applications using the programming tools provided with Microsoft Access. For more information about Visual Basic for Applications, please refer to your version of the "Building Applications with Microsoft Access" manual.

NOTE: Visual Basic for Applications is called Access Basic in Microsoft Access versions 1.x and 2.0. For more information about Access Basic, please refer to the "Introduction to Programming" manual in Microsoft Access version 1.x or the "Building Applications" manual in Microsoft Access version 2.0.

MORE INFORMATION

Microsoft Access sorts records in ascending or descending order without regard to case. However, you can use a user-defined function in a query to sort text data by its ASCII character values. This results in a case-sensitive order.

The following table demonstrates how the ascending order in Microsoft Access differs from a case-sensitive order:

   Ascending   Case-Sensitive
    Order          Order
   --------------------------
        a              A
        A              B
        B              C
        b              D
        c              a
        C              b
        D              c
        d              d 

1. Open an existing Microsoft Access database.



2. Create a new table with the following structure:

   
         Table: Sorting Test
         -------------------
         Field Name: Test
            Data Type: Text 




3. View the Sorting Test table in Datasheet view, type the following eight records in the Test field, and then close the table:

   b
   d
   B
   A
   D
   a
   C
   c




4. Create a module and type the following line in the Declarations section if it is not already there:

   Option Explicit




5. Type the following procedure:

   
         Function StrToHex (S As Variant) As Variant
         '
         ' Converts a string to a series of hexadecimal digits.
         ' For example, StrToHex(Chr(9) & "A~") returns 09417E.
         '
            Dim Temp As String, I As Integer
               If VarType(S) <> 8 Then
                  StrToHex = S
               Else
                  Temp = ""
               For I = 1 To Len(S)
                  Temp = Temp & Format(Hex(Asc(Mid(S, I, 1))), "00")
               Next I
               StrToHex = Temp
            End If
         End Function 




6. Create the following query based on the Sorting Test table:

   
         Query: CaseSensitive Sorting Test
         ---------------------------------
         Type: Select
         Field: Test
            Sort: not sorted
            Show: True
         Field: Expr1: StrToHex([Test])
            Sort: Ascending
            Show: False 




7. Run the query. Note that the records are sorted in case-sensitive order. The uppercase characters (A-D) appear before the lowercase characters (a-d).

REFERENCES

For more information about the Hex() function search the Help Index for "Hex function," or ask the Microsoft Access 97 Office Assistant.

Additional query words:

Keywords : kbusage
Version : WINDOWS:1.0,1.1,2.0,7.0,97
Platform : WINDOWS
Issue type : kbhowto