PRB: KEYMATCH Ignores SET DELETED and SET FILTER Settings

• Microsoft FoxPro for Windows, versions 2.6, 2.6a
• Microsoft FoxPro for MS-DOS, versions 2.6, 2.6a
• Microsoft FoxPro for Macintosh, versions 2.6, 2.6a

SYMPTOMS

The KEYMATCH() function added to FoxPro in versions 2.6 and later does not adhere to the settings of SET DELETED or SET FILTER.

CAUSE

The FoxPro versions 2.6 and 2.6a for Windows style help file states that KEYMATCH(); "Searches an index file or index tag for an index key and returns true (.T.) if the index key is found." The SET FILTER and SET DELETED commands only affect the table, not the index. Therefore, KEYMATCH() will not adhere to these settings.

RESOLUTION

For KEYMATCH() to acknowledge the settings of SET DELETED or SET FILTER, place the FILTER expression and DELETED setting in the index itself.

For Example, unless the same conditions of the SET FILTER expression and SET DELETED ON are added to the index, the following code will not give the desired results using the KEYMATCH() function. This example is set up to return a .T. using the Customer table where the record is not deleted, and the State is WA or NC:

   USE Customer
   DELETE TAG ALL   && So you can set KEYMATCH to first tag;
                    && Caution: This will delete all tags in Customer.CDX
   INDEX ON State TAG State
   SET DELETED ON
   SET FILTER TO State = "WA" OR State = "NC"
   ? KEYMATCH('WA',1,'Customer')

For the above example to return a .T., place the DELETED and FILTER conditions within the FOR clause of the Index expression as in this example:

   USE Customer
   DELETE TAG ALL   && So you can set KEYMATCH to first tag;
                    && Caution: This will delete all tags in Customer.CDX
   INDEX ON State FOR !DELETED() AND (State = "WA" OR State = "NC") ;
      TAG State
   ?KEYMATCH('WA',1,'Customer')

STATUS

This behavior is by design.