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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 ...
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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How to fix Python indentation
...py script that you find in the Tools/scripts/ directory of your Python installation:
Change Python (.py) files to use
4-space indents and no hard tab
characters. Also trim excess spaces
and tabs from ends of lines, and
remove empty lines at the end of
files. Also ensure the last line ...
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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How to update SQLAlchemy row entry?
...SERIALIZABLE transaction isolation-level, but to my understanding it would allow performing the addition in Python using the in-place addition. If there is a race, one of the transactions will then succeed and the others will fail and must retry (with the new state of the DB). But I might've misunde...
Find duplicate lines in a file and count how many time each line was duplicated?
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This is what I do however algorithmically this is doesnt seem to be the most efficient approach (O(n log n)*avg_line_len where n is number of lines). I'm working on files that are several gigabytes large, so performance is a key issue. I wonder whether there is ...
How to automatically crop and center an image
...can use background-size: cover; to get the image to shrink or fill the div appropriately while maintaining the original aspect ratio.
– Nick
Apr 30 '13 at 16:48
7
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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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Why am I getting an Exception with the message “Invalid setup on a non-virtual (overridable in VB) m
...ethods and sealed classes. While running a test using mock object, MOQ actually creates an in-memory proxy type which inherits from your "XmlCupboardAccess" and overrides the behaviors that you have set up in the "SetUp" method. And as you know in C#, you can override something only if it is marked ...
SQL injection that gets around mysql_real_escape_string()
...ly to SELECT passwd FROM users. In the latter case, the second query is usually executed by use of a UNION clause.
– Jacco
May 21 '12 at 9:47
59
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