Fabio,
>and these conditions have to return NULL (unknow),
>a condition that skip the row.
So far as a know to skip the row the select clause need to return .F.
Foxpro is not able to handle a unknow (.NULL.) where clause
that's why we have the ISNULL() function.
This code give a invalid where clause
CLEAR
CREATE CURSOR _TABLE (F1 INT NULL)
SELECT 2 FROM _TABLE T1 WHERE .NULL. INTO ARRAY zz
Marcel