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What's faster, SELECT DISTINCT or GROUP BY in MySQL?
...e databases implement DISTINCT under the hood).
If one of them is faster, it's going to be DISTINCT. This is because, although the two are the same, a query optimizer would have to catch the fact that your GROUP BY is not taking advantage of any group members, just their keys. DISTINCT makes this ...
How to remove “index.php” in codeigniter's path
How do I remove the "index.php" sticking out in every path in codeigniter somewhere in the center?
I want clean non index.php-fied URLs ?
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What is a lambda (function)?
For a person without a comp-sci background, what is a lambda in the world of Computer Science?
23 Answers
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Comment the interface, implementation or both?
...s a general rule, I use the same DRY (Don't Repeat Yourself) principle as with code:
on interface, document the interface
on implementation, document the implementation specifics
Java specific: when documenting the implementation, use {@inheritDoc} tag to "include" javadocs from the interface.
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Python nonlocal statement
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Compare this, without using nonlocal:
x = 0
def outer():
x = 1
def inner():
x = 2
print("inner:", x)
inner()
print("outer:", x)
outer()
print("global:", x)
# inner: 2
# outer: 1
# global: 0
To this, usi...
Using str_replace so that it only acts on the first match?
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Can be done with preg_replace:
function str_replace_first($from, $to, $content)
{
$from = '/'.preg_quote($from, '/').'/';
return preg_replace($from, $to, $content, 1);
}
echo str_replace_first('abc', '123', 'abcdef abcdef abcde...
Accept server's self-signed ssl certificate in Java client
It looks like a standard question, but I couldn't find clear directions anywhere.
12 Answers
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No Persistence provider for EntityManager named
I have my persistence.xml with the same name using TopLink under the META-INF directory.
Then, I have my code calling it with:
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Loading basic HTML in Node.js
... to find out how to load and render a basic HTML file so I don't have to write code like:
19 Answers
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Why is using onClick() in HTML a bad practice?
...JavaScript events, such as onClick() , in HTML is a bad practice, because it's not good for semantics. I would like to know what the downsides are and how to fix the following code?
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