Re: Trouble with FULL OUTER JOIN ... USING

USING does the same thing += does: it makes it harder to make a mistake.

MyLongFieldNameA = MyLongFieldNameAA + 1
vs
MyLongFieldNameA += 1

MYTABLE A join MYTABLE B
  on (A.KEY1, A.KEY2, A.KEY3) = (B.KEY2, B.KEY1, A.KEY3)
vs
MYTABLE A join MYTABLE B using (KEY1, KEY2, LEY3)

Second syntax avoid two popular errors, and by popular, I mean ones I do all the time :).  Wrong key name (or just simple transposition) and wrong table qualifier.


On 5/3/2020 12:03 PM, John Yeung wrote:

On Fri, May 1, 2020 at 12:34 PM Joe Pluta <joepluta@xxxxxxxxxxxxxxxxx> wrote:

I've run into variations of this issue alot over the years. The problem
is that the fields in the USING clause don't always work in a way that
is convenient.

Me too. I kind of gave up trying to learn when I could and couldn't
use USING, and just never absorbed it into my (very small) SQL
repertoire. All my joins just use ON, which I find much more
predictable and reliable.

Am I missing out on some significant advantage that USING confers?
From where I'm sitting, it's just a finicky bit of limited-use syntax
sugar for ON anyway.

John Y.