Hi Sarah: >From what I've hear, (I'm not a db expert but lots of my coworkers are) the simple query where it lists all tables separated by commas, translates to an inner join as seen in your example. But for simple left outer joins the comma separated query would translate to a more complex query which will outcome in a less optimal one. I would say that sql has its tools for making these complex query's into simple ones which will improve performance. I would also appreciate an easy to understand tutorial if anyone can suggest one. > > SELECT a.foo, a.field1, b.qux, b.field2 > FROM table1 as a, table2 as b > WHERE a.field1 = b.field2 > > and should be replaced with: > > SELECT a.foo, a.field1, b.qux, b.field2 > FROM table1 as a > INNER JOIN table2 as b > ON a.field1 = b.field2 > > Has anyone else heard this, and can they shed any light on it? I guess > I'm just wondering where this change came from, how important it is, do > I need to go back and re-work countless queries to use this syntax, etc? > > Also, if anyone has an easy-to-understand tutorial on JOIN clauses > (especially LEFT JOIN and the like), I'd really appreciate it - it's one > of those things that I understand but couldn't for the life of me > explain to someone else :) > -- Marianela Queme Guatemala "Life is beautiful"