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Ordering by the order of values in a SQL IN() clause
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Two solutions that spring to mind:
order by case id when 123 then 1 when 456 then 2 else null end asc
order by instr(','||id||',',',123,456,') asc
(instr() is from Oracle; maybe you have locate() or charindex() or something like that)
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Setting environment variables on OS X
What is the proper way to modify environment variables like PATH in OS X?
31 Answers
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Install a Windows service using a Windows command prompt?
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If the directory's name has a space like c:\program files\abc 123, then you must use double quotes around the path.
installutil.exe "c:\program files\abc 123\myservice.exe"
It makes things much easier if you set up a bat file like following,
e.g. To install a service, create a "my...
How to start a background process in Python?
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Note: This answer is less current than it was when posted in 2009. Using the subprocess module shown in other answers is now recommended in the docs
(Note that the subprocess module provides more powerful facilities for spawning new processes and retrieving their results; ...
Histogram Matplotlib
...ered Sep 4 '13 at 10:15
Matthias123Matthias123
79266 silver badges1313 bronze badges
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python: Change the scripts working directory to the script's own directory
...ent working directory to so that opening relative paths will work:
import os
os.chdir("/home/udi/foo")
However, you asked how to change into whatever directory your Python script is located, even if you don't know what directory that will be when you're writing your script. To do this, you can u...
Converting A String To Hexadecimal In Java
I am trying to convert a string like "testing123" into hexadecimal form in java. I am currently using BlueJ.
21 Answers
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Fastest check if row exists in PostgreSQL
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How about simply:
select 1 from tbl where userid = 123 limit 1;
where 123 is the userid of the batch that you're about to insert.
The above query will return either an empty set or a single row, depending on whether there are records with the given userid.
If this turns o...
How do I run Asynchronous callbacks in Playground
...swered Nov 25 '16 at 10:58
bradd123bradd123
9111 silver badge22 bronze badges
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Insert all values of a table into another table in SQL
...dited Feb 26 '14 at 1:12
hichris123
9,5151212 gold badges5050 silver badges6666 bronze badges
answered Apr 21 '10 at 9:35
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