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How to avoid “if” chains?
...nInAnyCase();
this will satisfy both of your requirements:
executeStep<X>() should evaluate only if the previous one succeeded (this is called short circuit evaluation)
executeThisFunctionInAnyCase() will be executed in any case
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Why historically do people use 255 not 256 for database field magnitudes?
...
<<
Recollected the fundamentals of the bits/bytes storage, it requires one byte to store integers below 256 and two bytes for any integer between 256 and 65536.
Hence, it requires same space (two bytes) to store 511 or ...
How do you write a migration to rename an ActiveRecord model and its table in Rails?
...
Here's an example:
class RenameOldTableToNewTable < ActiveRecord::Migration
def self.up
rename_table :old_table_name, :new_table_name
end
def self.down
rename_table :new_table_name, :old_table_name
end
end
I had to go and rename the model declaration fil...
What is the error “Every derived table must have its own alias” in MySQL?
...NCT customer_id, store_id FROM purchases)
GROUP BY customer_id HAVING 1 < SUM(1);
..will break with the error Every derived table must have its own alias. To fix:
SELECT DISTINCT customer_id, SUM(1)
FROM ( SELECT DISTINCT customer_id, store_id FROM purchases) AS custom
GROUP BY customer...
How to force cp to overwrite without confirmation
... and copying whatever you need to copy, you can set alias back to its default by doing alias cp='cp -i'. After which, run alias cp so you can verifiy that it's back to default alias.
– jaxarroyo
Nov 15 '18 at 18:33
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SQL Server SELECT LAST N Rows
...Orders
) as ordlist
WHERE ordlist.EmployeeID = 5
AND ordlist.OrderedDate <= 5
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How to resize an image with OpenCV2.0 and Python2.6
...I did not test the efficiency of the implementations, nor compared the results - so the end result may also differ slightly. Did you test to see the resized images match bitwise?
– emem
May 15 '17 at 12:06
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How to check whether a pandas DataFrame is empty?
... 1 2 22
2 3 33
# This data manipulation approach results in an empty df
# because of a subset of values that are not available (`NaN`)
In [2]: df = df[df['AA'] == 5]
df
Out[2]: Empty DataFrame
Columns: [AA, BB]
Index: []
# NOTE: the df is empty, BUT the...
What is the most appropriate way to store user settings in Android application
...ver to use a negotiated token for providing access, something like OAuth. Alternatively you may need to construct some sort of cryptographic store, though that's non-trivial. At the very least, make sure you're encrypting the password before writing it to disk.
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Regular expressions in an Objective-C Cocoa application
Initial Googling indicates that there's no built-in way to do regular expressions in an Objective-C Cocoa application.
10 A...