Comment 2 for bug 520150

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Robert Jordens (jordens) wrote : Re: multiple tables on the right side of a join should be put in parentheses

At least for mysql this is well defined:
http://dev.mysql.com/doc/refman/5.1/en/join.html

quoting:
The syntax of table_factor is extended in comparison with the SQL Standard. The latter accepts only table_reference, not a list of them inside a pair of parentheses. This is a conservative extension if we consider each comma in a list of table_reference items as equivalent to an inner join. For example:
SELECT * FROM t1 LEFT JOIN (t2, t3, t4) ON (t2.a=t1.a AND t3.b=t1.b AND t4.c=t1.c)
is equivalent to:
SELECT * FROM t1 LEFT JOIN (t2 CROSS JOIN t3 CROSS JOIN t4) ON (t2.a=t1.a AND t3.b=t1.b AND t4.c=t1.c)

OTOH sqlite then exhibits its invisible columns bug:
http://www.sqlite.org/cvstrac/tktview?tn=2060