CLEAR
CLOSE DATABASES ALL
CLOSE TABLES ALL
CREATE CURSOR byby (CC I )
APPEND BLANK

ON ERROR ??  MESSAGE()

SYS(3054,11)

? "WITHOUT A INDEX, VFP DEFINE A TEMPORARY INDEX"
test()

SELECT byby
INDEX ON CC TAG T1

? "IF A INDEX IS DEFINED, THE QUERY FAILS"
test()

CLOSE TABLES ALL
ON ERROR

PROCEDURE test

SELECT * FROM byby b2 INNER JOIN byby b1 ON B1.CC=NULL*B2.CC INTO CURSOR abra

SELECT * FROM byby b2 LEFT JOIN byby b1 ON B1.CC=NULL*B2.CC INTO CURSOR abra

SELECT * FROM byby b1 RIGHT JOIN byby b2 ON B1.CC=NULL*B2.CC INTO CURSOR abra

SELECT * FROM byby b2 FULL JOIN byby b1 ON B1.CC=NULL*B2.CC INTO CURSOR abra

SELECT * FROM FORCE byby b2 INNER JOIN byby b1 ON B1.CC=NULL*B2.CC INTO CURSOR abra

SELECT * FROM FORCE byby b2 LEFT JOIN byby b1 ON B1.CC=NULL*B2.CC INTO CURSOR abra

SELECT * FROM FORCE byby b1 RIGHT JOIN byby b2 ON B1.CC=NULL*B2.CC INTO CURSOR abra

SELECT * FROM FORCE byby b2 FULL JOIN byby b1 ON B1.CC=NULL*B2.CC INTO CURSOR abra
RETURN