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Unique fields that allow nulls in Django
...trings are equal to empty strings for uniqueness checks, under both Django and database rules.
You can force the admin interface to store NULL for an empty string by providing your own customized model form for Foo with a clean_bar method that turns the empty string into None:
class FooForm(forms....
How do I redirect in expressjs while passing some context?
...gs. You'll need to ensure that the values are properly encodeURIComponent and decodeURIComponent.
app.get('/category', function(req, res) {
var string = encodeURIComponent('something that would break');
res.redirect('/?valid=' + string);
});
You can snag that in your other route by getting t...
Check if a string contains an element from a list (of strings)
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With LINQ, and using C# (I don't know VB much these days):
bool b = listOfStrings.Any(s=>myString.Contains(s));
or (shorter and more efficient, but arguably less clear):
bool b = listOfStrings.Any(myString.Contains);
If you wer...
What is LINQ and what does it do? [closed]
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LINQ stands for Language Integrated Query.
Instead of writing YAQL (Yet Another Query Language), Microsoft language developers provided a way to express queries directly in their languages (such as C# and Visual Basic). The techniq...
Extending the User model with custom fields in Django
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The least painful and indeed Django-recommended way of doing this is through a OneToOneField(User) property.
Extending the existing User model
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If you wish to store information related to User, you can use a one-to-one relationship to a mo...
WITH CHECK ADD CONSTRAINT followed by CHECK CONSTRAINT vs. ADD CONSTRAINT
I'm looking at the AdventureWorks sample database for SQL Server 2008, and I see in their creation scripts that they tend to use the following:
...
Purpose of ESI & EDI registers?
What is the actual purpose and use of the EDI & ESI registers in assembler?
5 Answers
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How exactly does CMake work?
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The secret is that you don't have to understand what the generated files do.
CMake introduces a lot of complexity into the build system, most of which only pays off if you use it for building complex software projects.
The good news is that CMake does a good job of k...
Check if something is (not) in a list in Python
I have a list of tuples in Python , and I have a conditional where I want to take the branch ONLY if the tuple is not in the list (if it is in the list, then I don't want to take the if branch)
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How do I detect unsigned integer multiply overflow?
...ting a program in C++ to find all solutions of a b = c , where a , b and c together use all the digits 0-9 exactly once. The program looped over values of a and b , and it ran a digit-counting routine each time on a , b and ab to check if the digits condition was satisfied.
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