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Postgresql aggregate array
...
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 can I validate a string to only allow alphanumeric characters in it?
How can I validate a string using Regular Expressions to only allow alphanumeric characters in it?
10 Answers
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App store link for “rate/review this app”
... Note - the "type=Purple+Software" has to be there and it has to be literally "Purple Software" - it's not the name of your company, it's a codename for iPhone applications :) I wasted an hour before I figured this out...
– Kuba Suder
Oct 24 '11 at 11:27
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How to declare a variable in a PostgreSQL query
...WITH () query which can work as a variable, or even tuple of variables. It allows you to return a table of temporary values.
WITH master_user AS (
SELECT
login,
registration_date
FROM users
WHERE ...
)
SELECT *
FROM users
WHERE master_login = (SELECT login
...
Install Gem from Github Branch?
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You don't need to build the gem locally. In your gemfile you can specify a github source with a ref, branch or tag.
gem 'rails', :git => "git://github.com/rails/rails.git", :ref => "4aded"
gem 'rails', :git => "git://github.com/rails/rails.git", :bra...
difference between fork and branch on github
If I fork a project that's hosted on github. Do I fork all the branches? How do I know which branch my fork is based on? In other words which branch will be downloaded to my PC?
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Why doesn't Haskell's Prelude.read return a Maybe?
...ersions floating around many codebases).
See also this discussion.
Personally, I use the version from the safe package.
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How to generate all permutations of a list?
How do you generate all the permutations of a list in Python, independently of the type of elements in that list?
33 Answer...
Detect if called through require or directly by command line
How can I detect whether my Node.JS file was called using SH: node path-to-file or JS: require('path-to-file') ?
5 Answers...