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Postgresql aggregate array
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Use array_agg: http://www.sqlfiddle.com/#!1/5099e/1
SELECT s.name, array_agg(g.Mark) as marks
FROM student s
LEFT JOIN Grade g ON g.Student_id = s.Id
GROUP BY s.Id
By the way, if you are using Postgres 9.1, you don't need ...
How to run a single RSpec test?
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Usually I do:
rspec ./spec/controllers/groups_controller_spec.rb:42
Where 42 represents the line of the test I want to run.
EDIT1:
You could also use tags. See here.
EDIT 2:
Try:
bundle exec rspec ./spec/controllers/gro...
User recognition without cookies or local storage
...ople are so security-aware that it would be difficult to get people to install these kinds of programs on their system. This leaves you stuck with using Cookies and other, similar tools.
Cookies and other, similar tools
You might consider building a Data Profile, then using Probability tests to id...
CSS transition shorthand with multiple properties?
...n: height 0.3s ease-out, opacity 0.3s ease 0.5s;
Or just transition them all:
-webkit-transition: all 0.3s ease-out;
-moz-transition: all 0.3s ease-out;
-o-transition: all 0.3s ease-out;
transition: all 0.3s ease-out;
Here is a straightforward example. Here is another one with the delay propert...
Is there a way to filter network requests using Google Chrome developer tools?
... to filter out some requests using Chrome developer tools, say, filter out all image requests?
8 Answers
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What are the -Xms and -Xmx parameters when starting JVM?
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The flag Xmx specifies the maximum memory allocation pool for a Java virtual machine (JVM), while Xms specifies the initial memory allocation pool.
This means that your JVM will be started with Xms amount of memory and will be able to use a maximum of Xmx amount of ...
How can I quickly delete a line in VIM starting at the cursor position?
...atever was yanked before.
The true delete command in the OP's context is "_D (or "_C if insert mode is desired) This sends the deleted content into the black hole register, designated by "_, where it will bother no one ever again (although you can still undo this action using u).
That being said,...
What is the best django model field to use to represent a US dollar amount?
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I think this example is correct almost to all currencies. To represent currencies as Bitcoin, I think is much better to use an integer field to save the amount in satoshis, and then show it to the final user in the representation that you want (BTC, mBTC, etc)
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RESTful Authentication
...ZGRpbjpvcGVuIHNlc2FtZQ==
It's easy to implement, available by default on all browsers, but has some known drawbacks, like the awful authentication window displayed on the Browser, which will persist (there is no LogOut-like feature here), some server-side additional CPU consumption, and the fact t...
Merge (with squash) all changes from another branch as a single commit
In Git, is there a way to merge all changes from one branch into another, but squash to a single commit at the same time?
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