My question is why is the form
(anything) = NULL
allowed?
Since
(anything) = NULL is always Null, this cannot be what the coder intended.
This is much different when comparing two variables, where the coder may have to
handle the cases where the variables are Null. Here the comparison is to a
Rich Hall [EMAIL PROTECTED] writes:
My question is why is the form
(anything) = NULL
allowed?
If you think it shouldn't be, you can turn on the transform_null_equals
flag. However, past experience has shown that that breaks more things
than it fixes. In any case, few people like to depend on
NULL is handled like unknow
When you comparing something with an unknown value,
you are not able to say if they are equal or not.
So the result is also unknown.
The result NULL is correct.
If you whant to check if somethings is NULL
you have to use (anything) IS NULL
Rich Hall schrieb:
My
Rich Hall wrote:
My question is why is the form
(anything) = NULL
allowed?
Since
(anything) = NULL is always Null, this cannot be what the coder
intended.
Using that same line of argument, why is 1+1 allowed? The coder clearly
knows that it is 2, so why is he writing that? Many
On Tue, 29 Jun 2004, Greg Stark wrote:
Stephan Szabo [EMAIL PROTECTED] writes:
IS TRUE and IS FALSE have a different effect from =true and =false when
the left hand side is NULL. The former will return false, the latter will
return NULL.
No, actually they both return false.
For
Rich Hall [EMAIL PROTECTED] writes:
(anything) = NULL is always Null, this cannot be what the coder intended.
I often have such things in my SQL. Consider what happens when you have SQL
constructed dynamically. Or more frequently, consider that many drivers still
don't use the new binary
Stephan Szabo [EMAIL PROTECTED] writes:
IS TRUE and IS FALSE have a different effect from =true and =false when
the left hand side is NULL. The former will return false, the latter will
return NULL.
No, actually they both return false.
(But thanks, I didn't even realize they were special
You are exactly right - the way I think about it is that if you have two
values which are unknown (a null column and NULL) it does not follow
that they are equal to each other.
As far as TRUE and FALSE go, from what I know you can use = to compare
them with boolean columns, unless I misunderstood
Re,
thanks for all the replies.
On Tuesday, 29 June 2004 00:17, Dmitri Bichko wrote:
As far as TRUE and FALSE go, from what I know you can use = to compare
them with boolean columns, unless I misunderstood your question.
Sorry, I must have remembered that incorrectly, or maybe I've been
On Tue, 29 Jun 2004, Stefan Weiss wrote:
On Tuesday, 29 June 2004 00:17, Dmitri Bichko wrote:
As far as TRUE and FALSE go, from what I know you can use = to compare
them with boolean columns, unless I misunderstood your question.
Sorry, I must have remembered that incorrectly, or maybe
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