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How to create a unique index on a NULL column?
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Pretty sure you can't do that, as it violates the purpose of uniques.
However, this person seems to have a decent work around:
http://sqlservercodebook.blogspot.com/2008/04/multiple-null-values-in-unique-index-in.html
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JavaScript: Class.method vs. Class.prototype.method
... no relationship with an object instance of that constructor function, you can consider it like a 'static method'.
In JavaScript functions are first-class objects, that means you can treat them just like any object, in this case, you are only adding a property to the function object.
The second fu...
Which characters need to be escaped in HTML?
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If you're inserting text content in your document in a location where text content is expected1, you typically only need to escape the same characters as you would in XML. Inside of an element, this just includes the entity escape ampersand & and the element delimiter less-than...
E731 do not assign a lambda expression, use a def
...irst form means that the name of the resulting
function object is specifically 'f' instead of the generic '<lambda>'.
This is more useful for tracebacks and string representations in
general. The use of the assignment statement eliminates the sole
benefit a lambda expression can offer ...
What does this square bracket and parenthesis bracket notation mean [first1,last1)?
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∞ isn't an ordinal number, of the sort that you can do arithmetic with. But it's a valid cardinal number when answering questions like "How many integers are there?". It's also, as in this case, perfectly valid as a limit
– Kevin Wright
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Why can't the C# constructor infer type?
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Is there a philosophical reason why the constructor can't support type inference?
No. When you have
new Foo(bar)
then we could identify all types called Foo in scope regardless of generic arity, and then do overload resolution on each using ...
What's the role of GetHashCode in the IEqualityComparer in .NET?
...n of the object. Since there is no limit to how much information an object can contain, certain hash codes are shared by multiple objects - so the hash code is not necessarily unique.
A dictionary is a really cool data structure that trades a higher memory footprint in return for (more or less) co...
What is Autoloading; How do you use spl_autoload, __autoload and spl_autoload_register?
...plement new and useful methods. Earlier I was using __autoload just to escape including multiple files on each page, but recently I have seen a tip on __autoload manual
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Why does the JVM still not support tail-call optimization?
Two years after does-the-jvm-prevent-tail-call-optimizations , there seems to be a prototype implementation and MLVM has listed the feature as "proto 80%" for some time now.
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How do CUDA blocks/warps/threads map onto CUDA cores?
...have been using CUDA for a few weeks, but I have some doubts about the allocation of blocks/warps/thread.
I am studying the architecture from a didactic point of view (university project), so reaching peak performance is not my concern.
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