Too much free time - ANSII SQL question

[stmontgo]

So I got nothing better to do today so I'm messing with some ANSII sql.

Why would you ever want to use the ON clause?

For example, if I could use

SELECT e.employee_id, e.last_name, d.location_id
FROM employees e JOIN departments d USING (department_id)

Tnen why would I even think of using


SELECT e.employee_id, e.last_name, d.location_id
FROM employees e JOIN departments d ON (e.department_id = d.department_id)

The 9i new features book says using the ON clause makes your SQL code easier to read.

Any thoughts?

Thanks much

[stmontgo]

never mind, a 3 way join would be good for this, should have flipped on to the next page ;-)

[DaPi]

10 years ago the problem I had with Rdb's implementation of USING(department_id) was that neither d. nor e. aliases were allowed for the join column - it could only be refered to as "department_id". So if you had a third table with with a column "department_id" there was no simple way of resolving the ambiguity. (This may not be strict ANSII behaviour.)