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When saving, how can you check if a field has changed?
...erson(models.Model):
name = models.CharField()
__original_name = None
def __init__(self, *args, **kwargs):
super(Person, self).__init__(*args, **kwargs)
self.__original_name = self.name
def save(self, force_insert=False, force_update=False, *args, **kwargs):
...
PHP Error handling: die() Vs trigger_error() Vs throw Exception
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The first one should never be used in production code, since it's transporting information irrelevant to end-users (a user can't do anything about "Cannot connect to database").
You throw Exceptions if you know that at a certain criti...
Constructor overloading in Java - best practice
There are a few topics similar to this, but I couldn't find one with a sufficient answer.
6 Answers
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MySQL Query GROUP BY day / month / year
...I knew this earlier...so many lines of PHP to do something mysql can do in one line.
– nights
Nov 1 '18 at 3:01
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IntelliJ: Viewing diff of all changed files between local and a git commit/branch
...now been implemented. In order to compare two branches you do:
Check out one of the branches you want to compare with.
Select the branch you want to compare with in the Git branch popup in the status bar in the bottom right of the IntelliJ window. A popup with some options is shown.
Select the "Co...
Checkout another branch when there are uncommitted changes on the current branch
... somewhere permanent. You may want to use git stash to save them; this is one of the things it's designed for. Note that git stash save or git stash push actually means "Commit all the changes, but on no branch at all, then remove them from where I am now." That makes it possible to switch: you n...
Facebook API - How do I get a Facebook user's profile image through the Facebook API (without requir
... specify the picture size you want with the type argument, which should be one of square (50x50), small (50 pixels wide, variable height), normal (100 pixels wide, variable height), and large (about 200 pixels wide, variable height)" Via Graph API on Facebook
– user603284
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What is the Java string pool and how is “s” different from new String(“s”)? [duplicate]
...g:
In computer science, string interning
is a method of storing only one copy
of each distinct string value, which
must be immutable. Interning strings
makes some string processing tasks
more time- or space-efficient at the
cost of requiring more time when the
string is created or ...
Why does a return in `finally` override `try`?
...urnState;
}
}
Generally speaking you never want to have more than one return statement in a function, things like this are why.
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When to use extern in C++
...es the header knows about it, but you only need to “define” it once in one of your source files.
To clarify, using extern int x; tells the compiler that an object of type int called x exists somewhere. It's not the compilers job to know where it exists, it just needs to know the type and name s...