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Join vs. sub-query
...ery has no reference to foo it can be optimized by the DB-server as static content and could be evaluated only once.
Sub-queries in the Where-statement
SELECT moo FROM foo WHERE bar = (SELECT roger FROM wilco WHERE moo = me)
If you are lucky, the DB optimizes this internally into a JOIN. If not,...
Why is the minimalist, m>ex m>ample Haskell quicksort not a “true” quicksort?
...quicksort has two beautiful aspects:
Divide and conquer: break the problem into two smaller problems.
Partition the elements in-place.
The short Haskell m>ex m>ample demonstrates (1), but not (2). How (2) is done may not be obvious if you don't already know the technique!
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Remove rows with all or some NAs (missing values) in data.frame
I'd like to remove the lines in this data frame that:
16 Answers
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MFC OnEraseBkgnd浅析 - C/C++ - 清泛网 - 专注C/C++及内核技术
MFC OnEraseBkgnd浅析在使用VC进行绘图时，最郁闷的就是屏幕闪烁问题。有时只能使用双缓冲去解决，当然更多的时候是去忍受。有没有什么这种的方法？有，那就是重 在使用VC进行绘图时，最郁闷的就是屏幕闪烁问题。有时只能...
Is it possible to install iOS 6 SDK on Xcode 5?
...ou need.
SDKs can be found within the installer package at:
Xcode.app/Contents/Developer/Platforms/
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How to clear all s’ contents inside a parent ?
...).remove().html(); and get the divs inside #masterdiv of tmp and clear the contents and return
– Prasad
Nov 10 '09 at 10:24
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What is the easiest way to parse an INI file in Java?
I am writing a drop-in replacement for a legacy application in Java. One of the requirements is that the ini files that the older application used have to be read as-is into the new Java Application. The format of this ini files is the common windows style, with header sections and key=value pairs...
Generate a random date between two other dates
How would I generate a random date that has to be between two other given dates?
26 Answers
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Having Django serve downloadable files
...pResponse(mimetype='application/force-download') # mimetype is replaced by content_type for django 1.7
response['Content-Disposition'] = 'attachment; filename=%s' % smart_str(file_name)
response['X-Sendfile'] = smart_str(path_to_file)
# It's usually a good idea to set the 'Content-Length' header too...
How to generate and validate a software license key?
...games these days have given up on copy protection and simply take the game content online, in which case the code is out of the hacker's hands.
– JamieB
Dec 4 '12 at 22:56
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