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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...
Why is null an object and what's the difference between null and undefined?
...nown what the value is.
One thing to remember is that null is not, conceptually, the same as false or "" or such, even if they equate after type casting, i.e.
name = false;
You: What is name?
JavaScript: Boolean false.
name = '';
You: What is name?
JavaScript: Empty string
*: name in this context...
How to force use of overflow menu on devices with menu button
I'd like to have all of the menu items that don't fit into the ActionBar go into the overflow menu (the one that is reached from the Action Bar not the menu button) even on devices that do have a Menu button . This seems much more intuitive for users than throwing them into a separate menu list th...
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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Global variables in AngularJS
...lue. The problem with it is that the controller that initialises it, gets called again by angular some how and then resets the variable back to its initial value.
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How to get instance variables in Python?
Is there a built-in method in Python to get an array of all a class' instance variables? For example, if I have this code:
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How to check certificate name and alias in keystore files?
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In order to get all the details I had to add the -v option to romaintaz answer:
keytool -v -list -keystore <FileName>.keystore
share
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combinations between two lists?
...aving trouble wrapping my head around a algorithm I’m try to make. Basically, I have two lists and want to get all the combinations of the two lists.
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