Thanks for your responses,
Surely there is a plethora of bugs keeping devs busy where someone has
failed to consider the null case in a < > comparison which has
unintended results ?!
Especially considering the following c# code
|int? x = null;
if(x != 1)
Console.WriteLine("x is not 1");
else
Console.WriteLine("x is 1");|
and the 'same' thing in t-sql does the opposite...
On 18/01/2012 4:52 PM, Jano Petras wrote:
Hi Wallace,
I am always using ISNULL function for these cases when I am to compare.
Another possibility is to check for NULL explicitly:
IF @var IS NULL BEGIN
-- do stuff
END
ELSE BEGIN
-- do other stuff
END
Cheers,
jano
On 18 January 2012 08:20, Wallace Turner <[email protected]
<mailto:[email protected]>> wrote:
Consider:
|declare @var bit
if (select @var)<> 1
print 'value is not equal to 1'
else
print 'value is 1'
|
assuming ANSI_NULLS is on then the output is:
value is 1
What are some common ways that people deal with this 'gotcha' ? eg
1) don't use <> operator at all
2) use ISNULL
Please consider the case where the select is a (more) complex
statement.
Regards
Wal
