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Unique constraint that allows empty values in MySQL
I have a field that stores product codes. The codes are unique, but some products simply doesn't have a code. I can't invent codes because those are providers codes.
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Is it smart to replace boost::thread and boost::mutex with c++11 equivalents?
...us project manager thinks that boost is another dependency and that it is horrible because "you depend on it"(I tried explaining the quality of boost, then gave up after some time :( ). Smaller reason why I would like to do it is that I would like to learn c++11 features, because people will start w...
Run java jar file on a server as background process
I need to run a java jar in server in order to communicate between two applications. I have written two shell scripts to run it, but once I start up that script I can't shut down / terminate the process. If I press ctrl + C or close the console, the server will shut down. Could anyone help me how ...
How to check if element is visible after scrolling?
...ow you to call a utility function that accepts the element you're looking for and if you want the element to be fully in view or partially.
function Utils() {
}
Utils.prototype = {
constructor: Utils,
isElementInView: function (element, fullyInView) {
var pageTop = $(window).scrol...
What's so great about Lisp? [closed]
I don't know enough Lisp to say whether it's good or bad. It seems like everyone who has used Lisp loves it, yet the most popular languages these days are descended from C.
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Django fix Admin plural
How do I change some models name from "Categorys" to "Categories" on admin site in the new dev django version?
In the old version (whithout admin sites and admin models) you could just do this;
http://www.the-dig.com/blog/post/customize-plural-name-django-admin/
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Why doesn't Python have a sign function?
...+/-nan, etc)
So they decided to implement only copysign, which (although more verbose) can be used to delegate to the end user the desired behavior for edge cases - which sometimes might require the call to cmp(x,0).
I don't know why it's not a built-in, but I have some thoughts.
copysign(x,y):...
How can I join elements of an array in Bash?
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A 100% pure Bash function that supports multi-character delimiters is:
function join_by { local d=$1; shift; local f=$1; shift; printf %s "$f" "${@/#/$d}"; }
For example,
join_by , a b c #a,b,c
join_by ' , ' a b c #a , b , c
join_by ')|(' a b c #a)|(b)|(c
joi...
How to change the default font size in ggplot2
...e to change some default parameters of ggplot2 graphics, like font size for instance, for a whole R session. The idea is to avoid setting them for each plot.
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what does npm -D flag mean?
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The -D flag is the shortcut for: --save-dev. Source: https://docs.npmjs.com/cli/install
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