Which pair(s) of the three clauses consist(s) of equivalent ones please:
(1) FROM a LEFT JOIN b ON x=y LEFT JOIN c ON xx = yy
(2) FROM (a LEFT JOIN b ON x=y) LEFT JOIN c ON xx = yy
(3) FROM a LEFT JOIN (b LEFT JOIN c ON xx = yy) ON x=y
?
A) (1) is equivalent to (2)
B) (1) is equivalent to (3)
C) (2) is equivalent to (3)
D) All three are the same
E) All are different.
Do SQL standards say anything about JOIN associativity?
Thanks,
--Igor