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How to 'insert if not exists' in MySQL?
I started by googling, and found this article which talks about mutex tables.
10 Answers
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Python way of printing: with 'format' or percent form? [duplicate]
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Use the format method, especially if you're concerned about Python 3 and the future. From the documentation:
The formatting operations described here are modelled on C's printf()
syntax. They only support formatting of certain builtin types. The
use of a binary operator means ...
Imitate Facebook hide/show expanding/contracting Navigation Bar
...wing property:
@property (nonatomic) CGFloat previousScrollViewYOffset;
And here are the UIScrollViewDelegate methods:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGRect frame = self.navigationController.navigationBar.frame;
CGFloat size = frame.size.height - 21;
CGFloat...
How to write an async method with out parameter?
...el CLR rewrite instead of a
compiler-rewrite. We examined that approach, and it had a lot going
for it, but it would ultimately have been so costly that it'd never
have happened.
A typical workaround for this situation is to have the async method return a Tuple instead.
You could re-write yo...
scala vs java, performance and memory? [closed]
I am keen to look into Scala, and have one basic question I cant seem to find an answer to:
in general, is there a difference in performance and usage of memory between Scala and Java?
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What is the best way to remove accents (normalize) in a Python unicode string?
I have a Unicode string in Python, and I would like to remove all the accents (diacritics).
8 Answers
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Check whether a path is valid
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http:\\host/path/file
The string represents a hierarchical absolute Uri and does not contain "://".
www.example.com/path/file
The parser for the Uri.Scheme indicates that the original string was not well-formed.
The example depends on the scheme of the URI.
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Maven command to list lifecycle phases along with bound goals?
I'm just learning Maven, and so this might be obvious, but I can't find an easy way to list the goals associated for each maven lifecycle phase for a given project.
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How far can memory leaks go?
...erating system maintains: memory, open files, network connections, window handles...
That said, if the program is running on an embedded system without an operating system, or with a very simple or buggy operating system, the memory might be unusable until a reboot. But if you were in that situatio...
Creating an abstract class in Objective-C
...ct class - by making the methods/ selectors call doesNotRecognizeSelector: and therefore raise an exception making the class unusable.
For example:
- (id)someMethod:(SomeObject*)blah
{
[self doesNotRecognizeSelector:_cmd];
return nil;
}
You can also do this for init.
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