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Update multiple rows in same query using PostgreSQL
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You can also use update ... from syntax and use a mapping table. If you want to update more than one column, it's much more generalizable:
update test as t set
column_a = c.column_a
from (values
('123', 1),
('345', 2)
) as c(column_b, column_a)
wher...
What is the correct way to create a single-instance WPF application?
Using C# and WPF under .NET (rather than Windows Forms or console), what is the correct way to create an application that can only be run as a single instance?
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Google Maps: how to get country, state/province/region, city given a lat/long value?
...e. I need to store this information in a manner that hierarchy is preserve and without duplicates (e.g. "USA" and "United States" and "United States of America" are the same country; I only want one instance of this country in my database).
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How to pass command line arguments to a shell alias? [duplicate]
How do I pass the command line arguments to an alias? Here is a sample:
11 Answers
11
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What techniques can be used to speed up C++ compilation times?
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Language techniques
Pimpl Idiom
Take a look at the Pimpl idiom here, and here, also known as an opaque pointer or handle classes. Not only does it speed up compilation, it also increases exception safety when combined with a non-throwing swap function. The Pimpl idiom lets you reduce the depen...
Is it expensive to use try-catch blocks even if an exception is never thrown?
...rown, it now does a relatively expensive operation of walking up the stack and seeing if any try blocks exist that would catch this exception. From a layman's perspective, try may as well be free. It's actually throwing the exception that costs you - but unless you're throwing hundreds or thousands ...
Is there a way to cache GitHub credentials for pushing commits?
...chronizing my repositories to https:// on GitHub (due to firewall issues), and it asks for a password every time.
24 Answer...
Swift Programming: getter/setter in stored property
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var rank: Int = 0 {
didSet {
// Say 1000 is not good for you and 999 is the maximum you want to be stored there
if rank >= 1000 {
rank = 999
}
}
}
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How can we generate getters and setters in Visual Studio?
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Rather than using Ctrl + K, X you can also just type prop and then hit Tab twice.
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Naming returned columns in Pandas aggregate function? [duplicate]
I'm having trouble with Pandas' groupby functionality. I've read the documentation , but I can't see to figure out how to apply aggregate functions to multiple columns and have custom names for those columns.
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