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Django migration strategy for renaming a model and relationship fields
...kemigrations myapp command will ask you if you renamed your model. E.g.: Did you rename the myapp.Foo model to Bar? [y/N] If you answer 'y' your migration will contain the migration.RenameModel('Foo', 'Bar') Same counts for the renamed fields :-)
– ceasaro
Apr...
What's the difference between django OneToOneField and ForeignKey?
...del) and ForeignKey(SomeModel, unique=True). As stated in The Definitive Guide to Django:
OneToOneField
A one-to-one relationship. Conceptually, this is similar to a ForeignKey with unique=True, but the "reverse" side of the relation will directly return a single object.
In contrast to th...
How do I fix a NoSuchMethodError?
...hen running it.
Look at the stack trace ... If the exception appears when calling a method on an object in a library, you are most likely using separate versions of the library when compiling and running. Make sure you have the right version both places.
If the exception appears when calling a met...
How do you remove an array element in a foreach loop?
...y-filter.php): ARRAY_FILTER_USE_KEY - pass key as the only argument to callback instead of the value ARRAY_FILTER_USE_BOTH - pass both value and key as arguments to callback instead of the value Default is 0 which will pass value as the only argument to callback instead. That said, reading...
How to filter logcat in Android Studio?
...here is too much output, so I'd like to filter it using some keywords, basically displaying only the output containing the keyword(s). Is there a way to do that in Android Studio through the UI?
...
How to paste in a new line with vim?
...apping (unnecessary really, but just for completeness):
:nmap <F4> :call append(line('.'), @")<CR>
" This one may be a little better (strip the ending new-line before pasting)
:nmap <F4> :call append(line('.'), substitute(@", '\n$', '', ''))<CR>
:help let-register
:help :c...
Validating URL in Java
...se;
}
}
The constructor of URI checks that url is a valid URI, and the call to parseServerAuthority ensures that it is a URL (absolute or relative) and not a URN.
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Can enums be subclassed to add new elements?
... The reason I want to extend is because I'd like to have a base class called e.g. IntEnum, that looks like this: stackoverflow.com/questions/1681976/enum-with-int-value-in-java/…. Then all my enums could extend it...in this case just benefitting from inheritance and thus I wouldn't have to d...
Design Patterns: Factory vs Factory method vs Abstract Factory
...at is most alike to my understanding of these patterns. Adding examples of calling code (Client) would also help? Question that bothers me a lot is: can we say that Abstract Factory Pattern is just Factory extended with Factory Method Pattern (if this is true, I'm clear on this topic)?
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LINQ .Any VS .Exists - What's the difference?
...ll that it is hugely unlikely to take for example 0120012 seconds for 500k calls. And if it would be perfectly linear, thus explaining the numbers so nicely, 1M calls would've taken 0240024 seconds (twice as long), however that's not the case. 1M calls takes 58,(3)% longer than 500k and 10M takes 10...