DOCUMENT:Q173649 11-SEP-1997 [vbwin] TITLE :PRB: Memory Corruption in VB4-16 When Passing Recordset to Sub PRODUCT :Microsoft Visual Basic for Windows PROD/VER:WINDOWS:4.0 OPER/SYS:WINDOWS KEYWORDS:APrgDataAcc APrgDataOther vb416 VB4WIN ====================================================================== --------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual Basic Professional Edition, 16-bit only, for Windows, version 4.0 --------------------------------------------------------------------- SYMPTOMS ======== When passing a recordset to another Sub or Function, you see memory corruption or may experience a general protection fault (GP fault) in Vba5.dll. CAUSE ===== The called procedure may be declaring the recordset "As Object" instead of "As Recordset". RESOLUTION ========== Change the declaration in the called procedure to "As Recordset". STATUS ====== Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available. MORE INFORMATION ================ Microsoft provides code 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 code is provided 'as is' and Microsoft does not guarantee that the following code can be used in all situations. Microsoft does not support modifications of the code to suit customer requirements for a particular purpose. Steps to Reproduce Behavior --------------------------- 1. In Microsoft Access 2.0 or another front-end, create a Jet 2.x database (or use NWIND or BIBLIO) and add the following table: Table: Table1 Field: K1 Long Field: K2 Long Field: K3 Text (3) Field: Desc Text 2. Make a composite primary key, consisting of K1, K2, and K3, and then save the table design. 3. Add the following data: K1 K2 K3 Desc 1234 22222 abc xxxxxxxxxxx 1234 22222 def xxxxxxxxxxx 1234 22222 ghi xxxxxxxxxxx 1234 22222 jkl xxxxxxxxxxx 4. Create a Visual Basic 4.0 16-bit application. 5. Add a command button (Command1) to the form. 6. Add the following code to the form: option Explicit Private Sub Command1_Click() Dim db As Database, rs As Recordset Set db = DBEngine(0).OpenDatabase _ ("c:\office\access20\sampapps\nwind.mdb") ' alter as needed Set rs = db.OpenRecordset("Table1") rs.Index = "PrimaryKey" Test_Call rs rs.Close db.Close End Sub Sub Test_Call(rs As Object) Dim K1 As Long, K2 As Long, K3(3) As String, I As Long K1 = 1234 K2 = 22222 K3(0) = "abc" K3(1) = "def" K3(2) = "ghi" K3(3) = "jkl" Debug.Print "Pass 1" For I = 0 To 3 rs.Seek "=", K1, K2, K3(I) Debug.Print I; K1; K2; K3(0), K3(1), K3(2), K3(3) Next I Debug.Print "Pass 2" For I = 0 To 3 rs.Seek "=", K1, K2, K3(I) Debug.Print I; K1; K2; K3(0), K3(1), K3(2), K3(3) Next I Debug.Print "Pass 3" For I = 0 To 3 rs.Seek "=", K1, K2, K3(I) Debug.Print I; K1; K2; K3(0), K3(1), K3(2), K3(3) Next I End Sub 7. Make sure you change the .OpenDatabase method to correctly point to the database. 8. Run the application and click the command button. You may need to do this several times to see the error. Result ------ You should see either intermittent and worsening corruption of variables in the Debug Window, or you may get a GP fault in Vba5.dll. Workaround ---------- Change "Sub Test_Call (rs As Object)" to "Sub Test_Call(rs As Recordset)". NOTE: This problem does not appear in Visual Basic 4.0 32-bit. Additional query words: late-bound late bound vb4 ====================================================================== Keywords : APrgDataAcc APrgDataOther vb416 VB4WIN Component : dao jet Technology : ole Version : WINDOWS:4.0 Platform : WINDOWS 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 1997.