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Count(*) vs Count(1) - SQL Server
...not the case for Oracle or most other modern RDBMS but is the case for old MySQL's storage engine, MyISAM), then COUNT(*) would just need to take the value from the metadata.
– Quassnoi
Oct 31 '18 at 18:29
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Determine command line working directory when running node bin script
...s desirable to run an NPM script in the current directory, rather than the root of the project.
This variable is available inside npm package scripts as:
$INIT_CWD.
You must be running a recent version of NPM. If this variable is not available, make sure NPM is up to date.
This will allow you a...
Storing money in a decimal column - what precision and scale?
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For Mysql, I recommend storing the integer (2500) as a bigint if you intend on sorting by the amount. And don't waste your time with PHP 32bit when dealing with big integers, upgrade to 64bit or Node.JS ;)
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Dynamically Changing log4j log level
...ns of the configuration will pose a more in depth approach.
LogManager.getRootLogger().setLevel(Level.DEBUG);
The changes are permanent through the life cyle of the Logger. On reinitialization the configuration will be read and used as setting the level at runtime does not persist the level chang...
MIN/MAX vs ORDER BY and LIMIT
...OM `tbl`;
Simply because it is ANSI compatible. Limit 1 is particular to MySql as TOP is to SQL Server.
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Git alias with positional parameters
...ou use stronger magic like this.
UPD
Because commands are executed at the root of repository you may use ${GIT_PREFIX} variable when referring to the file names in commands
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How can I deploy/push only a subdirectory of my git repo to Heroku?
...ay via git-subtree. Assuming you want to push your folder 'output' as the root to Heroku, you can do:
git subtree push --prefix output heroku master
It appears currently that git-subtree is being included into git-core, but I don't know if that version of git-core has been released yet.
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Django - How to rename a model field using South?
...e slower than the 'rename_column' that other people have suggested. I know MySQL can do a "ALTER TABLE ... rename column" (or whatever it is) quite quickly.
– Rory
Jul 18 '11 at 10:01
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Standard deviation of a list
...n
stdev = st.pstdev(data)
Approach2: calculate variance and take square root of it
variance = st.pvariance(data)
devia = math.sqrt(variance)
Approach3: using basic math
mean = sum(data)/n
variance = sum([((x - mean) ** 2) for x in X]) / n
stddev = variance ** 0.5
print("{0:0.1f}".format(stdd...
Namespace not recognized (even though it is there)
... came to my mind. I looked at the path of my project and realized that the root folder, the one created by source tree, had "%20" instead of _ in the name. I changed it to _ and everything works fine now.
– Fernando Wolff
May 30 '19 at 19:04
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