BUG: REPLACE with UDF May Cause "Record Is Not Locked" Error

• Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0, 5.0a

SYMPTOMS

Using a user-defined function (UDF) that moves the record pointer in the currently selected table with a REPLACE command causes a "Record is not locked" error message. This error occurs if the buffering property is set to 2-Pessimistic record, 3-Optimistic record, or 5-Optimistic table.

WORKAROUND

Set the buffering property to 4-Pessimistic table. This locks the record and updates it after issuing the TABLEUPDATE() function.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Problem

1. Create a program called Test.prg containing the following code:

   SET MULTILOCKS ON SET EXCLUSIVE OFF SET DEFAULT TO SYS(2004)+"Samples\Data" OPEN DATABASE Testdata USE Customer =CURSORSETPROP("Buffering",2) GO 5 REPLACE maxordamt WITH mfunc() REPLACE maxordamt WITH mfunc() =TABLEUPDATE() =CURSORSETPROP("Buffering",1)

   FUNCTION mfunc ** Moves record from original position oldrec=IIF(EOF(),0,RECNO()) GO 1 tmp=maxordamt IF oldrec>0

         GO oldrec
   

   ENDIF RETURN tmp

2. Run the program. The error "Record is not locked" appears after encountering the second REPLACE command.

REFERENCES

For more information about the affect of SET EXCLUSIVE, please see the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q125732
   TITLE     : Cursor Created by User or ODBC Has EXCLUSIVE Status

   ARTICLE-ID: Q131031
   TITLE     : READ NOLOCK Behavior in Visual FoxPro