JOIN and AND in SQL
In this Section is all about one operator, JOIN. SQL's closest counterpart, NATURAL JOIN, has already been covered. Here we look at several other "join" operators defined in SQL. We don't really need to, as NATURAL JOIN, if considered as primitive, renders all the others redundant as shorthands. But as has already been mentioned, you won't find NATURAL JOIN in every SQL product. CROSS JOIN has already been mentioned as the operator implicitly used in joining the tables specified in a FROM clause's commalist.