Replying here as I don't want to sign up on medium. The blog indicates they believe SELECT * FROM table1, table2 ON table1.id=table2.id; is being parsed a

Replying here as I don't want to sign up on medium. The blog indicates they believe SELECT * FROM table1, table2 ON table1.id=table2.id; is being parsed as: SELECT result-column=* FROM table-or-subquery=table1 , join-clause=ON table1.id=table2.id table-or-subquery=table2 join-operator= EMPTY!! table-or-subquery=EMPTY!! join-constraint=ON table1.id=table2 This is not correct, it is being parsed as: SELECT result-column=* FROM join-clause=table1, table2 ON table1.id=table2.id table-or-subquery=table1 join-operator=, table-or-subquery=table2 join-constraint=ON table1.id=table2 In other words, because the constraint is present, both tables are part of the join clause, and `table1, table2` is just another way of writing `table1 JOIN table2`.