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Postgres: INSERT if does not exist already
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Postgres 9.5 (released since 2016-01-07) offers an "upsert" command, also known as an ON CONFLICT clause to INSERT:
INSERT ... ON CONFLICT DO NOTHING/UPDATE
It solves many of the subtle problems you can run into when using concurrent operation, which some other answers propose.
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Git blame — prior commits?
... Can you get a complete history, without having to re-enter the command several times with different hashes?
– Anders Zommarin
Feb 23 '11 at 22:59
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Git push existing repo to a new and different remote repo server?
Say I have a repository on git.fedorahosted.org and I want to clone this into my account at github to have my own playground aside from the more "official" repo on fedorahosted.
What would be the steps to initially copy that over?
Within github there is this nice "fork" button, but I can't use thi...
Detecting Browser Autofill
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The problem is autofill is handled differently by different browsers. Some dispatch the change event, some don't. So it is almost impossible to hook onto an event which is triggered when browser autocompletes an input field.
Change event trigger for d...
How do I detect a click outside an element?
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This breaks standard behaviour of many things, including buttons and links, contained within #menucontainer. I am surprised this answer is so popular.
– Art
Jun 12 '10 at 8:00
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What are Makefile.am and Makefile.in?
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Makefile.am is a programmer-defined file and is used by automake to generate the Makefile.in file (the .am stands for automake).
The configure script typically seen in source tarballs will use the Makefile.in to generate a Makefile.
The configure script itself is g...
C# LINQ find duplicates in List
... , how can I retrieve a list that contains entries repeated more than once and their values?
9 Answers
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What does -1 mean in numpy reshape?
... (-1,3) but not (-1, -1)). It simply means that it is an unknown dimension and we want numpy to figure it out. And numpy will figure this by looking at the 'length of the array and remaining dimensions' and making sure it satisfies the above mentioned criteria
Now see the example.
z = np.array([[...
Find number of months between two Dates in Ruby on Rails
...is solution does not consider days. The number of months between 28/4/2000 and 1/5/2000 is not 1 month, but 0.
– dgilperez
Aug 19 '13 at 18:39
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Passing a std::array of unknown size to a function
... answered Jun 17 '13 at 20:30
Andy ProwlAndy Prowl
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