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Foreign Key to multiple tables
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You have a few options, all varying in "correctness" and ease of use. As always, the right design depends on your needs.
You could simply create two columns in Ticket, OwnedByUserId and OwnedByGroupId, and have nullable Foreign Keys to each table.
You could create M:M referen...
Why doesn't await on Task.WhenAll throw an AggregateException?
...nto the actual exception.
So, in catch block, you get the actual exception and not the aggregated one. This helps us write more natural and intuitive code.
This was also needed for easier conversion of existing code into using async/await where the a lot of code expects specific exceptions and not a...
Getting individual colors from a color map in matplotlib
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You can do this with the code below, and the code in your question was actually very close to what you needed, all you have to do is call the cmap object you have.
import matplotlib
cmap = matplotlib.cm.get_cmap('Spectral')
rgba = cmap(0.5)
print(rgba) # (0.9...
How to automatically generate a stacktrace when my program crashes
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For Linux and I believe Mac OS X, if you're using gcc, or any compiler that uses glibc, you can use the backtrace() functions in execinfo.h to print a stacktrace and exit gracefully when you get a segmentation fault. Documentation can...
Turning off “created by” stamp when generating files in IntelliJ
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In IntelliJ 13 and above it is in the File and Code Templates area of the settings dialog. In Idea 15+ you can get there by typing ctrl+shift+A on windows or cmd+shift+A on osx and then typing Include Templates in the popup action search di...
How to trim whitespace from a Bash variable?
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Let's define a variable containing leading, trailing, and intermediate whitespace:
FOO=' test test test '
echo -e "FOO='${FOO}'"
# > FOO=' test test test '
echo -e "length(FOO)==${#FOO}"
# > length(FOO)==16
How to remove all whitespace (denoted by [:space:] in tr):
F...
Get Slightly Lighter and Darker Color from UIColor
...the brightness property itself. All in all:
@implementation UIColor (LightAndDark)
- (UIColor *)lighterColor
{
CGFloat h, s, b, a;
if ([self getHue:&h saturation:&s brightness:&b alpha:&a])
return [UIColor colorWithHue:h
saturation:s
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What is a “callable”?
...ue, yet o will still not be callable because Python skips __getattribute__ and __getattr__ for calls. The only real way left to check if something is callable is thus EAFP.
– L̲̳o̲̳̳n̲̳̳g̲̳̳p̲̳o̲̳̳k̲̳̳e̲̳̳
Jul 1 '10 at 23:03
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How do I define and use an ENUM in Objective-C?
I declared an enum in my implementation file as shown below, and declared a variable of that type in my interface as PlayerState thePlayerState; and used the variable in my methods. But I am getting errors stating that it is undeclared. How do I correctly declare and use a variable of type PlayerSta...
How to find all the tables in MySQL with specific column names in them?
I have 2-3 different column names that I want to look up in the entire DB and list out all tables which have those columns. Any easy script?
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