Re: difference between explicit inner join and implicit
>> Like this, you mean? <<
No, try this:
SELECT ..
FROM A, B, C
WHERE A.x BETWEEN B.y AND C.z;
Versus:
SELECT ..
FROM A
INNER JOIN
B
ON A.x >= B.y
INNER JOIN
C
ON C.z <= A.x;
The "between" is lost in what typographers call the law of proximity
because things are split into binary operators. Likewise, look around
this newsgroup for
a = x1 OR a = x2 or a = x3
versus
a IN (x1, x2, x3)
The set of matches is lost in the binary operators. My favorite
example of this mindset is
x1 = 0 OR x2 = 0 OR x3 = 0
versus
0 IN (x1, x2, x3)
Because the binary mindset is a left-to-right English based ordering
that says "x is zero" and "zero is x" when coding. I used to run into
this difference with Arab and Asian students who did not have this
cultural baggage.
|