FIX: Copy To ... Type SDF Causes Error Message in Visual FoxPro (172923)

SYMPTOMS

Issuing two consecutive COPY TO <filename> TYPE SDF commands causes Visual FoxPro 5.0x to return the following error message on the second command:

File <filename>.txt already exist as part of a database.

This error does not occur in Visual FoxPro 3.0b.

RESOLUTION

Check for the existence of the first SDF file and if it exists delete it. In the code example in the MORE INFORMATION section below, the following code accomplishes this task. Place the code between the two COPY TO commands:

   IF FILE("test1.txt")=.t.
      DELETE FILE test1.txt
   ENDIF

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This has been corrected in Visual FoxPro 6.0.

MORE INFORMATION

The error message occurs only when zero (0) is the first character in the SDF file. However, if the resulting SDF file is smaller than 8000 bytes, the error does not occur even if the zero character is in the SDF file. Finally, choosing any other file format or placing any other character in the SDF file prevents the error.

Steps to Reproduce Behavior

Create a program that contains the following code and execute it:

   CLEAR
   CREATE TABLE test1.dbf FREE (f C(100))
   FOR i = 1 TO 80
      INSERT INTO test1 VALUES ("0")
   NEXT
   COPY TO test1.txt TYPE SDF
   COPY TO test1.txt TYPE SDFF

The error appears on the second COPY TO command.