select a,last_note_user,c,d,iso_src from X,Y,Z left outer join W ON (W.last_note_user=Z.userid AND W.user_ten=Y.iso_src)
when I am executing the ab
You cannot mix JOIN syntaxes in Oracle this way.
JOIN
Oracle
A JOIN condition can only refer tables previously joined using ANSI JOIN syntax.
ANSI JOIN
Use this:
SELECT a, last_note_user, c, d, iso_src FROM X CROSS JOIN Y CROSS JOIN Z LEFT OUTER JOIN W ON W.last_note_user = Z.userid AND W.user_ten = Y.iso_src