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SQL join: selecting the last records in a one-to-many relationship
... customer c INNER JOIN
(SELECT RANK() OVER (PARTITION BY customer_id ORDER BY date DESC) r, *
FROM purchase) p
ON (c.id = p.customer_id)
WHERE p.r = 1
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How to determine CPU and memory consumption from inside a process?
...you will have to sample this file periodically, and calculate the diff, in order to determine the process's CPU usage over time.
Edit: remember that when you calculate your process's CPU utilization, you have to take into account 1) the number of threads in your process, and 2) the number of pro...
How to rollback a specific migration?
...e error in the original post)
rake db:migrate VERSION=20100905201547
In order to rollback ONLY ONE specific migration (OUT OF ORDER) use:
rake db:migrate:down VERSION=20100905201547
Note that this will NOT rollback any interceding migrations -- only the one listed. If that is not what you inte...
Setting PATH environment variable in OSX permanently
...
You have to add it to /etc/paths.
Reference (which works for me) : Here
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In pure functional languages, is there an algorithm to get the inverse function?
...x,-x]) [1..] will work, as this runs through the integers in the following order [0,1,-1,2,-2,3,-3, and so on]. Indeed inv (0 : concatMap (\x -> [x,-x]) [1..]) (+1) (-3) promptly returns -4!
The Control.Monad.Omega package can help you run through lists of tuples etcetera in a good way; I'm sure...
Import PEM into Java Key Store
...g to connect to an SSL server which requires me to authenticate myself. In order to use SSL over Apache MINA I need a suitable JKS file. However, I have only been given a .PEM file.
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C++ Singleton design pattern
...ingleton: How should it be used
See this two article about initialization order and how to cope:
Static variables initialisation order
Finding C++ static initialization order problems
See this article describing lifetimes:
What is the lifetime of a static variable in a C++ function?
See this ...
Reverse / invert a dictionary mapping
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Fun Fact: Dictionaries will be ordered (by time of insertion) in Python 3.7 onwards.
– byxor
Jun 12 '18 at 20:18
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Defining a HTML template to append using JQuery
...
In order to solve this problem, I recognize two solutions:
The first one goes with AJAX, with which you'll have to load the template from another file and just add everytime you want with .clone().
$.get('url/to/template', fu...
OAuth: how to test with local URLs?
... allow test auth api on localhost using http://webporject.dev or .loc and .etc and google short link that shortened your local url(http://webporject.dev) also bit.ly :). Google accepts only url which starts http://localhost/...
if you want to test google auth api you should follow these steps ...
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