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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...
Iterate over a Javascript associative array in sorted order
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You cannot iterate over them directly, but you can find all the keys and then just sort them.
var a = new Array();
a['b'] = 1;
a['z'] = 1;
a['a'] = 1;
function keys(obj)
{
var keys = [];
for(var key in obj)
{
if(obj.hasOwnProperty(key))
{
keys.pus...
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...
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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sql ORDER BY multiple values in specific order?
Ok I have a table with a indexed key and a non indexed field.
I need to find all records with a certain value and return the row.
I would like to know if I can order by multiple values.
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PostgreSQL error 'Could not connect to server: No such file or directory'
...n your postgres directory, probably /usr/local/var/postgres/
remove this and start server.
Check - https://github.com/mperham/lunchy is a great wrapper for launchctl.
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Add swipe to delete UITableViewCell
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if (editingStyle == UITableViewCellEditingStyle.Delete) {
// handle delete (by removing the data from your array and updating the tableview)
}
}
Swift 3.0:
override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
overrid...
Where to define custom error types in Ruby and/or Rails?
...ou define exceptions in this way:
gem_dir/lib/gem_name/exceptions.rb
and defined as:
module GemName
class AuthenticationError < StandardError; end
class InvalidUsername < AuthenticationError; end
end
an example of this would be something like this in httparty
For Ruby on Rails
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Unicode character as bullet for list-item in CSS
...probably go for an image background, they're much more efficient versatile and cross-browser-friendly.
Here's an example:
<style type="text/css">
ul {list-style:none;} /* you should use a css reset too... ;) */
ul li {background:url(images/icon_star.gif) no-repeat 0 5px;}
</style>
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Numpy matrix to array
I am using numpy. I have a matrix with 1 column and N rows and I want to get an array from with N elements.
9 Answers
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