Thread: RE: [HACKERS] Outer Joins (and need CASE help)

RE: [HACKERS] Outer Joins (and need CASE help)

From
"Jackson, DeJuan"
Date:

> -----Original Message-----
> > I could be wrong (I don't have a copy of the standard), but I don't
> > believe that the above syntax follows the standard.  Let me know if 
> > I'm wrong, but my understanding of the syntax would be more like:
> >  SELECT * FROM t1 JOIN t2 ON (t1.i = t2.i);
> > with the same result set as you listed (t2.i isn't suppressed).
> > This would have a difference in approach from the above.  
> If I wanted 
> > to join on columns with different names I couldn't use your 
> syntax (as 
> > one example).
> 
> The standard allows both syntaxes; USING is simpler to type, and ON is
> more general, as you point out.
> 
> In fact, the standard is annoyingly helpful in allowing 
> multiple ways to
> write the same query. Makes the parsing and parse tree transformation
> more complicated :(
Sorry for the extra work load, but hey that's cool.

>                           - Tom-DEJ