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How do you delete an ActiveRecord object?
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It's destroy and destroy_all methods, like
user.destroy
User.find(15).destroy
User.destroy(15)
User.where(age: 20).destroy_all
User.destroy_all(age: 20)
Alternatively you can use delete and delete_all which won't enforce :before_destro...
Specifically, what's dangerous about casting the result of malloc?
... therefore converting the void* pointer actually returned by malloc to int and then to your pointer type due to the explicit cast. On some platforms, int and pointers may take up different numbers of bytes, so the type conversions may lead to data corruption.
Fortunately, modern compilers give warn...
What are attributes in .NET?
What are attributes in .NET, what are they good for, and how do I create my own attributes?
11 Answers
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Django South - table already exists
I am trying to get started with South. I had an existing database and I added South ( syncdb , schemamigration --initial ).
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How do I create a link using javascript?
I have a string for a title and a string for a link. I'm not sure how to put the two together to create a link on a page using Javascript. Any help is appreciated.
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Is there an alternative sleep function in C to milliseconds?
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Yes - older POSIX standards defined usleep(), so this is available on Linux:
int usleep(useconds_t usec);
DESCRIPTION
The usleep() function suspends execution of the calling thread for
(at least) usec microseconds. T...
Routes with Dash `-` Instead of Underscore `_` in Ruby on Rails
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With Rails 3 and later you can do like this:
resources :user_bundles, :path => '/user-bundles'
Another option is to modify Rails, via an initializer.
I don't recommend this though, since it may break in future versions (edit: does...
How to install PyQt4 on Windows using pip?
... sure you grab the correct Windows wheel file (python version, 32/64 bit), and then use pip to install it - e.g:
C:\path\where\wheel\is\> pip install PyQt4-4.11.4-cp35-none-win_amd64.whl
Should properly install if you are running an x64 build of Python 3.5.
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What is a “callback” in C and how are they implemented?
From the reading that I have done, Core Audio relies heavily on callbacks (and C++, but that's another story).
9 Answers
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Openssl is not recognized as an internal or external command
...integrated with Facebook. In one of Facebook's tutorials, I found this command:
15 Answers
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