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count(*) vs count(column-name) - which is more correct? [duplicate]
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COUNT(*) counts all rows
COUNT(column) counts non-NULLs only
COUNT(1) is the same as COUNT(*) because 1 is a non-null expressions
Your use of COUNT(*) or COUNT(column) should be based on the desired output only.
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Getting key with maximum value in dictionary?
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@oba2311 max_value = max(stats.values()); {key for key, value in stats.items() if value == max_value}
– A. Coady
Apr 4 '17 at 0:37
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How do I show a Save As dialog in WPF?
...alog dialog = new SaveFileDialog()
{
Filter = "Text Files(*.txt)|*.txt|All(*.*)|*"
};
if (dialog.ShowDialog() == true)
{
File.WriteAllText(dialog.FileName, fileText);
}
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improve th...
What is the difference between lock and Mutex?
...hine.
bool firstInstance;
Mutex mutex = new Mutex(false, @"Local\DASHBOARD_MAIN_APPLICATION", out firstInstance);
if (!firstInstance)
{
//another copy of this application running
}
else
{
//run main application loop here.
}
// Refer to the mutex down here so garbage collection doesn't chu...
lenses, fclabels, data-accessor - which library for structure access and mutation is better
...f these libraries also provide a bunch of extra combinators on top, and usually some form of template haskell machinery to automatically generate lenses for the fields of simple record types.
With that in mind, we can turn to the different implementations:
Implementations
fclabels
fclabels is pe...
How can I get rid of an “unused variable” warning in Xcode?
...as an "unused" attribute you can use to suppress that warning:
BOOL saved __attribute__((unused)) = [moc save:&error];
Alternatively (in case LLVM doesn't support the above), you could split the variable declaration into a separate line, guaranteeing that the variable would be "used" whether ...
How to get these two divs side-by-side?
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#parent_div_1, #parent_div_2, #parent_div_3 {
width: 100px;
height: 100px;
border: 1px solid red;
margin-right: 10px;
float: left;
}
.child_div_1 {
float: left;
margin-right: 5px;
}
Check working example at http://js...
What does %w(array) mean?
....], curly braces %w{...} or even something like exclamation marks %w!...!. All of these have the same behavior (returning an array).
– ryanb
Aug 13 '09 at 21:40
146
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How to set focus on input field?
...nction ($timeout, $parse) {
return {
//scope: true, // optionally create a child scope
link: function (scope, element, attrs) {
var model = $parse(attrs.focusMe);
scope.$watch(model, function (value) {
console.log('value=', value);
...
Completion block for popViewController
...where animated {
coordinator.animateAlongsideTransition(nil) { _ in
completion()
}
} else {
completion()
}
}
func popViewController(animated: Bool, completion: () -> ()) {
popViewControllerAnimated(animated)
...