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Retrieving the last record in each group - MySQL
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MySQL 8.0 now supports windowing functions, like almost all popular SQL implementations. With this standard syntax, we can write greatest-n-per-group queries:
WITH ranked_messages AS (
SELECT m.*, ROW_NUMBER() OVER (PARTITION BY name ORDER BY id DESC) AS rn
FROM messages AS m...
Possible to do a MySQL foreign key to one of two possible tables?
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What you're describing is called Polymorphic Associations. That is, the "foreign key" column contains an id value that must exist in one of a set of target tables. Typically the target tables are related in some way, such as being instances of some c...
jQuery ui dialog change title after load-callback
...m an UI Dialog after i have submitted a form in this UI Dialog. So in the callback-function after load i should suggest, but i've tried and googled without result.
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In Python, how do I create a string of n characters in one line of code?
...ly, of course;-).
Other ways to "make a string of 10 characters": 'x'*10 (all the ten characters will be lowercase xs;-), ''.join(chr(ord('a')+i) for i in xrange(10)) (the first ten lowercase letters again), etc, etc;-).
sh...
How to get the number of Characters in a String?
..."), utf8.RuneCountInString("世界"))
}
Phrozen adds in the comments:
Actually you can do len() over runes by just type casting.
len([]rune("世界")) will print 2. At leats in Go 1.3.
And with CL 108985 (May 2018, for Go 1.11), len([]rune(string)) is now optimized. (Fixes issue 24923)
The compile...
How to retrieve an element from a set without removing it?
...r(s)) only exceeds list(s)[0] by three characters and is otherwise dramatically superior in both time and space complexity. So, while the claim of "least code" is trivially true, it's also trivially true that this is the worst possible approach. Even manually removing and then re-adding the removed ...
RESTfully design /login or /register resources?
...ounter. [...]
[... H]andling [of GET requests] by the server is not technically limited in any way. Therefore, careless or deliberate programming can cause non-trivial changes on the server. This is discouraged, because it can cause problems for Web caching, search engines and other automated agents...
What is a stack trace, and how can I use it to debug my application errors?
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In simple terms, a stack trace is a list of the method calls that the application was in the middle of when an Exception was thrown.
Simple Example
With the example given in the question, we can determine exactly where the exception was thrown in the application. Let's have a lo...
Reload .profile in bash shell script (in unix)?
I'm new to bash shell scripting, and have come across a challenge. I know I can reload my ".profile" file by just doing:
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FFmpeg: How to split video efficiently?
I wish to split a large avi video into two smaller consecutive videos. I am using ffmpeg.
9 Answers
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