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Can a foreign key be NULL and/or duplicate?
...answer: Yes, it can be NULL or duplicate.
I want to explain why a foreign key might need to be null or might need to be unique or not unique. First remember a Foreign key simply requires that the value in that field must exist first in a different table (the parent table). That is all an FK is by d...
C# List of objects, how do I get the sum of a property
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Alex LEAlex LE
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How do I drag and drop files into an application?
...vironment, but I'm not sure how to go about it for a C# application I'm working on. Are there best practices or gotchas to look out for?
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What are the “must have” jQuery plugins? [closed]
I'd like to know what are the most useful JQuery plugins. I'm particularly interested in those which are likely to be useful in general UI development, such as Tablesorter , rather than those which serve uncommon needs.
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How do I run Python code from Sublime Text 2?
... which should be at the bottom of the editor.
To Stop:
Ctrl + Break or Tools -> Cancel Build
Fn + C (OSX)
You can find out where your Break key is here: http://en.wikipedia.org/wiki/Break_key.
Note: CTRL + C will NOT work.
What to do when Ctrl + Break does not work:
Go ...
How do I get a list of column names from a psycopg2 cursor?
I would like a general way to generate column labels directly from the selected column names, and recall seeing that python's psycopg2 module supports this feature.
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Changes in import statement python3
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Relative import happens whenever you are importing a package relative to the current script/package.
Consider the following tree for example:
mypkg
├── base.py
└── derived.py
Now, your derived.py requires something from base.py. In Python 2, you could do it like th...
Use of 'use utf8;' gives me 'Wide character in print'
..., map { ord } split //, "鸡\n";'
233:184:161:10
The first three bytes make up your character, the last one is the line-feed.
The call to print sends these four characters to STDOUT. Your console then works out how to display these characters. If your console is set to use UTF8, then it will inte...
Credit card expiration dates - Inclusive or exclusive?
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It took me a couple of minutes to find a site that I could source for this.
The card is valid until the last day of the month indicated, after the last [sic]1
day of the next month; the card cannot be used to make a purchase ...
Passing an array by reference
How does passing a statically allocated array by reference work?
5 Answers
5
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