On 10/8/06, Jim C. Nasby <jim@xxxxxxxxx> wrote:
On Thu, Oct 05, 2006 at 09:30:45AM -0400, Merlin Moncure wrote: > I personally only use explicit joins when doing outer joins and even > them push them out as far as possible. I used to be like that too, until I actually started using join syntax. I now find it's *way* easier to identify what the join conditions are, and to seperate them from the rest of the where clause. It also makes it pretty much impossible to mess up a join clause and get a cartesian product. If you are going to put the join clauses in the WHERE clause, at least put a space between the join stuff and the rest of the WHERE clause.
I use the row constructor to define key relationships for non trivial queries i.e. select foo.*, bar.* from foo f, bar b where (f.a, f.b, f.c) = (b.a, b.b, b.c) -- etc I am a really big fan of the row constructor, especially since we can do proper key ordering in 8.2. by convention I do relating first, filtering second. for really complex queries I will inline comment each line of the where clause: where (p.a) = (pd.b) and -- match part to part description pd.type != 'A' -- not using archived parts as to unwanted cartesian products, I test all prodution queries in the shell first. The really complex ones are somewhat trial and error process after all these years :) being something of a mathematical guy, I love sql for its (mostly) functional nature but hate the grammar. reminds me a little bit too much of cobol. the join syntax is just too much for me, although with left/right/natural joins there is no other way, and I very much agree with Carlo wrt oracle's nonstandard join syntax being more elegant. merlin
