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How to map and remove nil values in Ruby
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Ruby 2.7 is introducing filter_map for this exact purpose. It's idiomatic and performant, and I'd expect it to become the norm very soon.
For example:
numbers = [1, 2, 5, 8, 10, 13]
enum.filter_map { |i| i * 2 if i.even? }
# => [4, 16, 20]
In your case, as the block evaluates to falsey, simp...
PostgreSQL Autoincrement
I'm switching from MySQL to PostgreSQL and was wondering how I can do autoincrement values. I saw in the PostgreSQL docs a datatype "serial", but I get syntax errors when using it (in v8.0).
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Run an app on a multiple devices automatically in Android Studio
... device. Is there any way to deploy the app on a multiple devices automatically - by clicking Run or even better with a shortcut?
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How to fix 'sudo: no tty present and no askpass program specified' error?
...type:
sudo visudo
Then edit that file to add to the very end:
username ALL = NOPASSWD: /fullpath/to/command, /fullpath/to/othercommand
eg
john ALL = NOPASSWD: /sbin/poweroff, /sbin/start, /sbin/stop
will allow user john to sudo poweroff, start and stop without being prompted for password.
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Semicolons superfluous at the end of a line in shell scripts?
...e superfluous, since the newline is also a command separator. case specifically needs double semicolons at the end of the last command in each pattern block; see help case for details.
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Is there any difference between DECIMAL and NUMERIC in SQL Server?
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They are the same. Numeric is functionally equivalent to decimal.
MSDN: decimal and numeric
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MySQL “NOT IN” query
I wanted to run a simple query to throw up all the rows of Table1 where a principal column value is not present in a column in another table ( Table2 ).
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When NOT to use yield (return) [duplicate]
...is h deep. Then there will at most points be O(h) nested iterators built. Calling "MoveNext" on the outer iterator will then make O(h) nested calls to MoveNext. Since it does this O(n) times for a tree with n items, that makes the algorithm O(hn). And since the height of a binary tree is lg n <=...
How to load db:seed data into test database automatically?
...ore every test or just once at the beginning. You could put it in a setup call or in a test_helper.rb file.
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What are the -Xms and -Xmx parameters when starting JVM?
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The flag Xmx specifies the maximum memory allocation pool for a Java virtual machine (JVM), while Xms specifies the initial memory allocation pool.
This means that your JVM will be started with Xms amount of memory and will be able to use a maximum of Xmx amount of ...