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postgresql - sql - count of `true` values
...his works:
SELECT count(*) AS total
, sum(myCol::int) AS countTrue --convert Boolean to Integer
FROM yourTable
;
or better (to avoid :: and use standard SQL syntax):
SELECT count(*) AS total
, sum(CAST(myCol AS int)) AS countTrue --convert Boolean to Integer
FROM yourTable
;
...
How to properly check if std::function is empty in C++11?
... an empty lambda doesn't really make sense. Behind the scenes the compiler converts a lambda expression into a struct (or class) definition, with the variables you capture stored as data members of this struct. A public function call operator is also defined, which is what allows you to invoke the l...
Default template arguments for function templates
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On Windows, with all versions of Visual Studio you can convert this error (C4519) to a warning or disable it like so:
#ifdef _MSC_VER
#pragma warning(1 : 4519) // convert error C4519 to warning
// #pragma warning(disable : 4519) // disable error C4519
#endif
See more details ...
Fastest way to determine if an integer's square root is an integer
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Wow! I'll try to convert this to Java and do a comparison, as well as an accuracy check on the results. I'll let you know what I find.
– Kip
Jan 12 '09 at 21:47
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What is the correct syntax for 'else if'?
...[2][0]("test")
except KeyError,e:
print "Invalid option: ",e
else:
sys.exit()
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How to create module-wide variables in Python? [duplicate]
...f for the current module instead of the current instance !
# db.py
import sys
# this is a pointer to the module object instance itself.
this = sys.modules[__name__]
# we can explicitly make assignments on it
this.db_name = None
def initialize_db(name):
if (this.db_name is None):
# a...
Convert character to ASCII code in JavaScript
How can I convert a character to its ASCII code using JavaScript?
10 Answers
10
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Convert decimal to hexadecimal in UNIX shell script
In a UNIX shell script, what can I use to convert decimal numbers into hexadecimal? I thought od would do the trick, but it's not realizing I'm feeding it ASCII representations of numbers.
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Get final URL after curl is redirected
...done < all_videos_link.txt
Results:
real 1m40.832s
user 0m9.266s
sys 0m15.375s
2. Without follow location
time while read -r line; do
curl -kIs -w "%{redirect_url}\n" -o /dev/null $line
done < all_videos_link.txt
Results:
real 0m51.037s
user 0m5.297s
sys 0m8.094s
...
Generate a random date between two other dates
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Convert both strings to timestamps (in your chosen resolution, e.g. milliseconds, seconds, hours, days, whatever), subtract the earlier from the later, multiply your random number (assuming it is distributed in the range [0, ...