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Fastest way to get the first object from a queryset in django?
...eturn None if there aren't any. There are lots of ways to do this which all work. But I'm wondering which is the most performant.
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Where does gcc look for C and C++ header files?
...stem header.
If you run gcc in verbose mode on such a source, it will list all the system include locations as it looks for the bogus header.
$ echo "#include <bogus.h>" > t.c; gcc -v t.c; rm t.c
[..]
#include "..." search starts here:
#include <...> search starts here:
/usr/local...
What is the use of the @ symbol in PHP?
...om error handler function with set_error_handler() then it will still get called, but this custom error handler can (and should) call error_reporting() which will return 0 when the call that triggered the error was preceded by an @...
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Is there any “font smoothing” in Google Chrome?
...e that explains it clearly and the few snippets I have found don't work at all.
5 Answers
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Is it possible to get all arguments of a function as single object inside that function?
...t an "Object which has a length property of a non-negative Integer, and usually some indexed properties." From the mozilla link: "It is similar to an Array, but does not have any Array properties except length."
– Luke
Aug 7 '17 at 13:09
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How to truncate a foreign key constrained table?
...ata integrity.
Option 1:
Remove constraints
Perform TRUNCATE
Delete manually the rows that now have references to nowhere
Create constraints
Option 2: suggested by user447951 in their answer
SET FOREIGN_KEY_CHECKS = 0;
TRUNCATE table $table_name;
SET FOREIGN_KEY_CHECKS = 1;
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What is an example of the Liskov Substitution Principle?
...the abstraction of having Square inherit from Rectangle is a bad one.
Y'all should check out the other priceless SOLID Principles Motivational Posters.
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CSS background image alt attribute
This is one I have not had to tackle before. I need to use alt tags on all images in a site including those used by CSS background-image attribute.
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List All Redis Databases
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Or you can just run the following command and you will see all databases of the Redis instance without firing up redis-cli:
$ redis-cli INFO | grep ^db
db0:keys=1500,expires=2
db1:keys=200000,expires=1
db2:keys=350003,expires=1
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C++ - passing references to std::shared_ptr or boost::shared_ptr
...now that sp->do_something() will not blow up due to a null pointer?
It all depends what is in those '...' sections of the code. What if you call something during the first '...' that has the side-effect (somewhere in another part of the code) of clearing a shared_ptr to that same object? And wha...