I'm old too. As far as I'm concerned, LEFT JOIN is simply shorthand for LEFT OUTER JOIN, and is semantically equivalent to a RIGHT JOIN, but with the order of

I'm old too. As far as I'm concerned, LEFT JOIN is simply shorthand for LEFT OUTER JOIN, and is semantically equivalent to a RIGHT JOIN, but with the order of the tables reversed. If what you really need is an INNER JOIN, and you use a LEFT JOIN instead, then you have a load of processing to do on the result-set. So if this guru "Jared" is only ever using LEFT JOIN, then either he's addressing a rather constrained problem space, or he's isn't that much of a SQL guru. Maybe he designs schemas in which LEFT joins are always equivalent to INNER joins? [Edit] I'm wrong; you can, of course, get the effect of an INNER JOIN by using a LEFT JOIN with a NOT NULL join condition. But I find the latter hard to read: there must be some reason this guy has used an outer join here, when it looks as if an inner join fits the bill?