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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 ;
share
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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...
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...
Best way to work with dates in Android SQLite [closed]
...at, the default if you use datetime('now') (yyyy-MM-dd HH:mm:ss) will then allow sorting by the date column.
Retrieving dates as strings from SQLite you can then format/convert them as required into local regionalised formats using the Calendar or the android.text.format.DateUtils.formatDateTime me...
Rename multiple files based on pattern in Unix
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Not present on all *nix systems. Not on Max OS X for one, and no package in fink to get it. Haven't looked at MacPorts.
– dmckee --- ex-moderator kitten
Jul 6 '09 at 16:07
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Forward function declarations in a Bash or a Shell script?
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This seems somewhat analogous to what if _ _ name _ _ == "_ _ main _ _": main() does in python
– Sergiy Kolodyazhnyy
Feb 13 '16 at 7:13
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Why would finding a type's initializer throw a NullReferenceException?
....cs:
(196c.1874): Access violation - code c0000005 (first chance)
mscorlib_ni!System.RuntimeType.GetConstructorImpl(System.Reflection.BindingFlags, System.Reflection.Binder, System.Reflection.CallingConventions, System.Type[], System.Reflection.ParameterModifier[])+0xa3:
000007fe`e5735403 488b4608 ...
Why are dates calculated from January 1st, 1970?
...1st, 1970) as default standard
The Question makes two false assumptions:
All time-tracking in computing is done as a count-since-1970.
Such tracking is standard.
Two Dozen Epochs
Time in computing is not always tracked from the beginning of 1970 UTC. While that epoch reference is popular, various...
What generates the “text file busy” message in Unix?
...table while it was running.
For example, I was building a make workalike called rmk, and after a while it was self-maintaining. I would run the development version and have it build a new version. To get it to work, it was necessary to use the workaround:
gcc -g -Wall -o rmk1 main.o -L. -lrmk -L...
Convert unix time to readable date in pandas dataframe
...12.15
3 1349979305 12.19
4 1350065705 12.15
In [25]: df['date'] = pd.to_datetime(df['date'],unit='s')
In [26]: df.head()
Out[26]:
date price
0 2012-10-08 18:15:05 12.08
1 2012-10-09 18:15:05 12.35
2 2012-10-10 18:15:05 12.15
3 2012-10-11 18:15:05 12.19
4 2012-10-12 18:15:...