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Why does NULL = NULL evaluate to false in SQL server
In SQL server if you have nullParam=NULL in a where clause, it always evaluates to false. This is counterintuitive and has caused me many errors. I do understand the IS NULL and IS NOT NULL keywords are the correct way to do it. But why does SQL server behave this way?
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When should static_cast, dynamic_cast, const_cast and reinterpret_cast be used?
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static_cast is the first cast you should attempt to use. It does things like implicit conversions between types (such as int to float, or pointer to void*), and it can also call explicit conversion functions (or implicit ones). In many cases, explicitly stating static_cast isn't ne...
How can I troubleshoot my Perl CGI script?
...is answer is intended as a general framework for working through
problems with Perl CGI scripts and originally appeared on Perlmonks as Troubleshooting Perl CGI Scripts. It is not a complete guide to every
problem that you may encounter, nor a tutorial on bug squashing. It
is just the culmination ...
What __init__ and self do on Python?
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In this code:
class A(object):
def __init__(self):
self.x = 'Hello'
def method_a(self, foo):
print self.x + ' ' + foo
... the self variable represents the instance of the object itself. Most object-oriented languages pass this as a hidden p...
Explain “claims-based authentication” to a 5-year-old
...ix has a pretty good answer, but to step away from the technical aspect of it:
Claims Based Authentication is about defining who you trust to give you accurate information about identity, and only ever using that information provided. My (the) go-to example is at a bar. Imagine for a moment that ...
Understanding garbage collection in .NET
...ns because you are using a debugger. You'll need to run your code the way it runs on your user's machine. Switch to the Release build first with Build + Configuration manager, change the "Active solution configuration" combo in the upper left corner to "Release". Next, go into Tools + Options, De...
What is uint_fast32_t and why should it be used instead of the regular int and uint32_t?
So the reason for typedef :ed primitive data types is to abstract the low-level representation and make it easier to comprehend ( uint64_t instead of long long type, which is 8 bytes).
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optional local variables in rails partial templates: how do I get out of the (defined? foo) mess?
...emplates to set default values for local variables if a value wasn't explicitly defined in the :locals hash when rendering the partial --
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Using i and j as variables in Matlab
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Because i and j are both functions denoting the imaginary unit:
http://www.mathworks.co.uk/help/matlab/ref/i.html
http://www.mathworks.co.uk/help/matlab/ref/j.html
So a variable called i or j will override them, potentially silently breaking code that does complex maths.
Possible...
Merging: Hg/Git vs. SVN
I often read that Hg (and Git and...) are better at merging than SVN but I have never seen practical examples of where Hg/Git can merge something where SVN fails (or where SVN needs manual intervention). Could you post a few step-by-step lists of branch/modify/commit/...-operations that show where S...