When using JOINS by the simply supplying a comma separated list of tables in
the FROM clause, is the ON argument normally associated with a join intended
to be addressed in the WHERE clause, or should ON still be used?
// Comma separated join
SELECT u.*, a.city FROM users u, addresses a WHERE u.id=a.user_id;
// Actual JOIN clause
SELECT u.*, a.city FROM users u INNER JOIN addresses a ON u.id=a.user_id;
// Query style in question
SELECT u.*, a.city FROM users u, addresses a ON u.id=a.user_id;
If not ON, is there at least another viable argument? The reason I'm
interested is for a query involving 5 or 6 tables and WHERE arguments which
do not deal with the relationships. I would like to assure the efficiency
of this query.
Thanks in advance,