DOCUMENT:Q129933 11-JAN-2001 [vbwin] TITLE :PRB: Comparing Bookmarks Generates Type Mismatch Error PRODUCT :Microsoft Visual Basic for Windows PROD/VER:WINDOWS:4.0 OPER/SYS: KEYWORDS:kbcode ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual Basic Professional Edition, 16-bit, for Windows, version 4.0 - Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0 - Microsoft Visual Basic Enterprise Edition, 16-bit, for Windows, version 4.0 - Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0 ------------------------------------------------------------------------------- SYMPTOMS ======== If you attempt to use the Bookmark property in a compare operation with another bookmark, you receive the following error if the bookmarks are not first stored in string variables: Run-time error 13 - Type Mismatch CAUSE ===== This is by design. Bookmarks in Visual Basic version 4.0 are stored in byte arrays. Arrays cannot be directly compared to each other. RESOLUTION ========== Before accessing the Bookmark property, copy the bookmark values to string variables, and make all comparisons using the string variables. The following code compares two bookmarks correctly. Step-by-Step Example -------------------- 1. Start a new project in Visual Basic. Form1 is created by default. 2. In the click event for Form1, place the following code: Private Sub Form_Click() Dim Db As Database Dim Rs As Recordset Dim Cs As Recordset Dim sBook1 as String Dim sBook2 as String Set Db = DBEngine.Workspaces(0).OpenDatabase("biblio.mdb") Set Rs = Db.OpenRecordset("authors", dbOpenDynaset) Set Cs = Rs.Clone() sBook1 = Rs.Bookmark sBook2 = Cs.Bookmark If sBook1 = sBook2 Then MsgBox "Match" Else MsgBox "No Match" End If End Sub 3. Run the program by pressing the F5 key. STATUS ====== This behavior is by design. MORE INFORMATION ================ Steps to Reproduce Problem -------------------------- Use the above example, but replace the code in the Form_Click procedure with this code: Private Sub Form_Click() Dim Db As Database Dim Rs As Recordset Dim Cs As Recordset Set Db = DBEngine.Workspaces(0).OpenDatabase("biblio.mdb") Set Rs = Db.OpenRecordset("authors", dbOpenDynaset) Set Cs = Rs.Clone() If Rs.Bookmark = Cs.Bookmark Then 'Error 13 - Type Mismatch MsgBox "Match" else MsgBox "No Match" End If End Sub Additional query words: 4.00 vb4win vb4all ====================================================================== Keywords : kbcode Technology : kbVBSearch kbAudDeveloper kbVB400Search kbVB400 kbVB16bitSearch Version : WINDOWS:4.0 Issue type : kbprb ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.