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Unique constraint on multiple columns
...o I add a unique constraint for columns fcode, scode, dcode with t-sql and/or management studio ? fcode, scode, dcode must be unique together.
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Compare two Byte Arrays? (Java)
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You can use both Arrays.equals() and MessageDigest.isEqual(). These two methods have some differences though.
MessageDigest.isEqual() is a time-constant comparison method and Arrays.equals() is non time-constant and it may bring some security issues if you ...
ASP.Net MVC Html.HiddenFor with wrong value
... modelState[fullName].Value = new ValueProviderResult(metadata.Model, Convert.ToString(metadata.Model), currentValue.Culture);
}
else
{
modelState[fullName] = new ModelState
{
Value = new ValueProviderResult(metadata.Model, Convert...
Android - Handle “Enter” in an EditText
I am wondering if there is a way to handle the user pressing Enter while typing in an EditText , something like the onSubmit HTML event.
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What do two question marks together mean in C#?
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It's the null coalescing operator, and quite like the ternary (immediate-if) operator. See also ?? Operator - MSDN.
FormsAuth = formsAuth ?? new FormsAuthenticationWrapper();
expands to:
FormsAuth = formsAuth != null ? formsAuth : new FormsAuthenticationWr...
What is the intent of the methods getItem and getItemId in the Android class BaseAdapter?
I'm curious about the purpose of the methods getItem and getItemId in the class Adapter in the Android SDK.
6 Answers
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How to print out the contents of a vector?
... a supplement to the above iterator solution. If you are using the C++11 standard (or later), then you can use the auto keyword to help the readability:
for (auto i = path.begin(); i != path.end(); ++i)
std::cout << *i << ' ';
But the type of i will be non-const (i.e., the compiler ...
Why doesn't C have unsigned floats?
...If C++ did support it, then you would be sometimes using an unsigned float and not realizing that your performance has just been killed. If C++ supported it then every floating point operation would need to be checked to see if it is signed or not. And for programs that do millions of floating poi...
Multiple levels of 'collection.defaultdict' in Python
...possibilities offered by collections.defaultdict , notably in readability and speed. I have put them to use with success.
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What is the difference between encode/decode?
... for instance transfer it over the network, or save it to a disk file.
To convert a string of bytes to a unicode string is known as decoding. Use unicode('...', encoding) or '...'.decode(encoding).
Example:
>>> u'æøå'
u'\xc3\xa6\xc3\xb8\xc3\xa5' # the interpreter prints the uni...