FIX: DBF() & RECCOUNT() Return Wrong Info About SQL Cursor

WINDOWS   | MS-DOS

The information in this article applies to:

• Microsoft FoxPro for Windows, versions 2.5x, 2.6x
• Microsoft FoxPro for MS-DOS, versions 2.5x, 2.6x

SYMPTOMS

Using the RECCOUNT() or DBF() functions against a cursor returns information pertinent to the source data file instead of the currently selected cursor.

CAUSE

If a WHERE clause is used that references a field that is used as a key field in a .CDX index tag, the DBF() and RECCOUNT() functions will return data about the source data file instead of the cursor. This is because, in this case, the SQL-SELECT performs a SET FILTER on the current table, and returns the filtered information. Use the _TALLY variable to return the number of records processed by the SQL-SELECT command.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This problem was corrected in Visual FoxPro 3.0 for Windows.

MORE INFORMATION

This behavior will occur regardless of the status of the SET ORDER command. However, this behavior does NOT occur under Microsoft Windows NT.

Steps to Reproduce Problem

In the steps below, you will be using the CUSTOMER database (which contains 500 records) in the TUTORIAL subdirectory. Make certain that the .CDX file is active, and that it includes a tag built on CNO.

1. In the Command window, issue the following commands:

         CLEAR ALL
         USE <FoxPro_directory>\tutorial\customer.dbf
         SELECT * FROM customer WHERE customer.cno = 'A'
   

   Note that 29 records are selected.

2. In the Command window, issue the following command:

         ? DBF()
   

   Note that it returns the name of the source file, not the temporary cursor name.

3. In the Command window, issue the following command:

         ? RECCOUNT()
   

For comparison, do the following:

1. In the Command window, issue the following command:

         CLEAR ALL
   

2. Remove the tag on the CNO field.

3. Repeat steps 1-3 above, but change the SELECT statement to:

         SELECT * FROM customer WHERE customer.cno = 'A'