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MySQL Cannot drop index needed in a foreign key constraint
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You have to drop the foreign key. Foreign keys in MySQL automatically create an index on the table (There was a SO Question on the topic).
ALTER TABLE mytable DROP FOREIGN KEY mytable_ibfk_1 ;
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How to set up Spark on Windows?
... http://spark.apache.org/docs/latest/building-spark.html
Download and install Maven, and set MAVEN_OPTS to the value specified in the guide.
But if you're just playing around with Spark, and don't actually need it to run on Windows for any other reason that your own machine is running Windows, I'd...
How to wait for a BackgroundWorker to cancel?
...Async();
_resetEvent.WaitOne(); // will block until _resetEvent.Set() call made
}
void worker_DoWork(object sender, DoWorkEventArgs e)
{
while(!e.Cancel)
{
// do something
}
_resetEvent.Set(); // signal that worker is done
}
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Perl build, unit testing, code coverage: A complete working example
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It took me a while and it also took me taking small snippets from a number of different sources and melting them together, but I think I have a small working example that sufficiently demonstrates to a Perl newbie the Perl build process including unit testing and code cove...
When should I use ugettext_lazy?
I have a question about using ugettext and ugettext_lazy for translations.
I learned that in models I should use ugettext_lazy , while in views ugettext.
But are there any other places, where I should use ugettext_lazy too? What about form definitions?
Are there any performance diffrences betwe...
Uninstall / remove a Homebrew package including all its dependencies
I have a Homebrew formula that I wish to uninstall/remove along with all its dependencies, skipping packages whom other packages depend upon (a.k.a. Cascading package removal in Package manager parlance).
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Javascript - Open a given URL in a new tab by clicking a button
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+1, if something opens a page in new tab, it is logically a link, so <a> tag is appropriate. Styles should be used to make it look like a button.
– Kos
May 9 '18 at 6:41
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In Python, using argparse, allow only positive integers
...still need to define an actual method that decides this for you:
def check_positive(value):
ivalue = int(value)
if ivalue <= 0:
raise argparse.ArgumentTypeError("%s is an invalid positive int value" % value)
return ivalue
parser = argparse.ArgumentParser(...)
parser.add_argu...
Django DB Settings 'Improperly Configured' Error
...--settings=mysite.settings (or whatever settings module you use)
Set DJANGO_SETTINGS_MODULE environment variable in your OS to mysite.settings
(This is removed in Django 1.6) Use setup_environ in the python interpreter:
from django.core.management import setup_environ
from mysite import settings
s...
Change the Target Framework for all my projects in a Visual Studio Solution
I need to change the target framework for all projects. I have many solutions with hundreds of projects.
10 Answers
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