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How to create a MySQL hierarchical recursive query
...
name,
parent_id
from (select * from products
order by parent_id, id) products_sorted,
(select @pv := '19') initialisation
where find_in_set(parent_id, @pv)
and length(@pv := concat(@pv, ',', id))
Here is a fiddle.
Here, the value specified in @pv := '19...
Where is PHP.ini in Mac OS X Lion? Thought it was in /usr/local/php5/lib
... on my Mac, uncommented httpd.conf, activated web sharing, installed MySQL etc.
I can't seem to find my PHP files, most importantly, PHP.ini.
...
.htaccess not working apache
...able Apache mod_rewrite module
a2enmod rewrite
add the following code to /etc/apache2/sites-available/default
AllowOverride All
Restart apache
/etc/init.d/apache2 restart
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Correct idiom for managing multiple chained resources in try-with-resources block?
...r comments: simplest is (2) to use Closeable resources and declare them in order in the try-with-resources clause. If you only have AutoCloseable, you can wrap them in another (nested) class that just checks that close is only called once (Facade Pattern), e.g. by having private bool isClosed;. In p...
How to handle multiple cookies with the same name?
...is to say:
The user agent SHOULD sort the cookie-list in the following order:
Cookies with longer paths are listed before cookies with shorter paths.
NOTE: Not all user agents sort the cookie-list in this order, but this
order reflects common practice when this document was wri...
Does “display:none” prevent an image from loading?
... by providing some context to it.
And you can still use some CSS magic in order to hide the image on small devices:
<style>
picture { display: none; }
@media (min-width: 600px) {
picture {
display: block;
}
}
</style>
<picture>
<source srcset="the-real-i...
Find nearest latitude/longitude with an SQL query
...S(latitude / 57.3), 2)) AS distance
FROM TableName HAVING distance < 25 ORDER BY distance;
where [starlat] and [startlng] is the position where to start measuring the distance.
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Macro vs Function in C
...ator though... overlooked that... But it might still be less readable.)
Order of Operations: (courtesy of @ouah)
#define min(a,b) (a < b ? a : b)
min(x & 0xFF, 42)
gets expanded to:
(x & 0xFF < 42 ? x & 0xFF : 42)
But & has lower precedence than <. So 0xFF < 42 ...
Singleton: How should it be used
...arginally more reliable in languages without a well-defined initialization order, this usage is still the moral equivalent of a global variable. It's a global variable dressed up in some awkward syntax (foo::get_instance() instead of g_foo, say), but it serves the exact same purpose (a single objec...
Difference between JSONObject and JSONArray
...gt;value pairs, tuples or whatever you want to call them)
like {ID : 1}
Order of elements is not important
a JSONObject of {id: 1, name: 'B'} is equal to {name: 'B', id: 1}.
JSONArray:
Contains only series values
like [1, 'value']
Order of values is important
array of [1,'value'] is ...