SQL JOIN: is there a difference between USING, ON or WHERE?

Question

I was wondering if there is any difference in the way SQL performs on these join statements:

SELECT * FROM a,b WHERE a.ID = b.ID

SELECT * FROM a JOIN b ON a         


        

Answer 1

The difference is readability and maintainability. SELECT * FROM a JOIN b ON a.ID = b.ID conveys your exact intent, all in the same place.

I won't say definitively since I haven't gotten under the hood of the last query optimizer, but I'm pretty confident you're looking at a trivial difference in performance, if any.