ACC: How to Create a Password Protected Form or Report

• Microsoft Access versions 7.0, 97

SUMMARY

Advanced: Requires expert coding, interoperability, and multiuser skills.

Microsoft Access has two built-in security features for protecting your database: User/Group accounts and permissions, and database passwords.

This article shows you how you can also set individual passwords for each form and report in your database.

MORE INFORMATION

Microsoft provides programming examples for illustration only, without warranty either expressed or implied, including, but not limited to, the implied warranties of merchantability and/or fitness for a particular purpose. This article assumes that you are familiar with the programming language being demonstrated and the tools used to create and debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific needs. If you have limited programming experience, you may want to contact the Microsoft fee-based consulting line at (800) 936-5200. For more information about the support options available from Microsoft, please seethe following page on the World Wide Web:

   http://www.microsoft.com/supportnet/refguide/

The following example shows you how you can password protect the Orders form in the sample database Northwind.mdb:

1. Open the sample database Northwind.mdb.

2. Create a module and type the following procedure:

         Public Function KeyCode(Password As String) As Long
            ' This function will produce a unique key for the
            ' string that is passed in as the Password.
            Dim I As Integer
            Dim Hold As Long
   
            For I = 1 To Len(Password)
               Select Case (Asc(Left(Password, 1)) * I) Mod 4
               Case Is = 0
                  Hold = Hold + (Asc(Mid(Password, I, 1)) * I)
               Case Is = 1
                  Hold = Hold - (Asc(Mid(Password, I, 1)) * I)
               Case Is = 2
                  Hold = Hold + (Asc(Mid(Password, I, 1)) * _
                     (I - Asc(Mid(Password, I, 1))))
               Case Is = 3
                  Hold = Hold - (Asc(Mid(Password, I, 1)) * _
                     (I + Len(Password)))
            End Select
            Next I
            KeyCode = Hold
         End Function
   
   

3. Create a new table as follows:

         Table: tblPassword
         ---------------------------
         Field Name: ObjectName
            Data Type: Text
            Field Size: 50
         Field Name: KeyCode
            Data Type: Number
            Field Size: Long Integer
            Input Mask: Password
   
         Table Properties: tblPassword
         -----------------------------
         PrimaryKey: ObjectName
   
   

4. Open the tblPassword table and enter the following data:

         ObjectName: Orders
         KeyCode: 2818
   

5. Open the Orders form in Design view.

6. Set the form's OnOpen property to the following event procedure:

         Private Sub Form_Open(Cancel as Integer)
            Dim Hold As Variant
            Dim tmpKey As Long
            Dim I As Integer
            Dim rs As Recordset
            Dim db As Database
   
            On Error GoTo Error_Handler
            ' Check to see if the user is passing in the Password.
            If IsNull(Me.OpenArgs) Then
               Hold = InputBox("Please your Password", "Enter Password")
            Else
               Hold = Me.OpenArgs
            End If
            ' Open the table that contains the password.
            Set db = CurrentDb
            Set rs = db.OpenRecordset("tblPassword", dbOpenTable)
            rs.Index = "PrimaryKey"
            rs.Seek "=", Me.Name
            If rs.NoMatch Then
               MsgBox "Sorry cannot find password info. Please Try Again"
               Cancel = -1
            Else
               ' Test to see if the key generated matches the key in
               ' the table; if there is not a match, stop the form
               ' from opening.
               If Not (rs![keycode] = KeyCode(Cstr(Hold))) Then
                  MsgBox "Sorry you entered the wrong password.  " & _
                     "Please try again.", vbOKOnly, "Incorrect Password"
                  Cancel = -1
               End If
            End If
            rs.Close
            db.Close
            Exit Sub
   
         Error_Handler:
            MsgBox Err.Description, vbOKOnly, "Error #" & Err.Number
            Exit Sub
         End Sub
   
   

7. Close and save the Orders form.

8. Open the Orders form and enter "PASSWORD" when prompted for a password.

   Note the Orders form opens.

9. Close and reopen the Orders form and enter "PassWord" when prompted for a password.

   Note that you receive the message "Sorry you entered the wrong password. Please try again." and the Orders form does not open.

    ?KeyCode("TestString")

To hide the tblPassword table in the Database window, right-click on the tblPassowrd table and click Properties. In the properties window click the Hidden check box, and then click OK.