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Rails Migration: Remove constraint
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have used it in postgresql. rails defines it in the database specific adapter see postgres, mysql. can search for others in apidock. So, will have to check the database adapter for support, in case anyone gets a NotImplementedError
– deepak
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rspec 3 - stub a class method
... for help, clarification, or responding to other answers.Making statements based on opinion; back them up with references or personal experience.To learn more, see our tips on writing great answers.
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Why does ConcurrentHashMap prevent null keys and values?
...ining the source code it appears I was wrong - they lock using a "segment" based on a bitmask of the hash.
In that case, I suspect they did it to copy Hashtable, and I suspect Hashtable did it because in the relational database world, null != null, so using a null as a key has no meaning.
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Function overloading in Javascript - Best practices
...ave a lot of flexibility
Take an object as the argument and use prototype based inheritance to add flexibility.
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Java: getMinutes and getHours
...alendar.get(Calendar.MONTH); // gets month number, NOTE this is zero based!
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What is the Bash equivalent of Python's pass statement
... for help, clarification, or responding to other answers.Making statements based on opinion; back them up with references or personal experience.To learn more, see our tips on writing great answers.
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Sleeping in a batch file
...sagree with the answers I found here.
I use the following method entirely based on Windows XP capabilities to do a delay in a batch file:
DELAY.BAT:
@ECHO OFF
REM DELAY seconds
REM GET ENDING SECOND
FOR /F "TOKENS=1-3 DELIMS=:." %%A IN ("%TIME%") DO SET /A H=%%A, M=1%%B%%100, S=1%%C%%100, ENDIN...
Why do people still use primitive types in Java?
...lds. You get an Integer created for you automatically when you need a heap based java object, and you get the speed and efficiency of an int when you are just doing arithmetic and local calculations.
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ASP.NET Identity reset password
...r your user is not null. This may happen for users migrated from other databases, or users which were not created through UserManager.CreateAsync() method.
– Alisson
Jul 18 '18 at 2:49
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Convert a number range to another range, maintaining ratio
... it works without having to reverse the ranges. Linear range conversion is based upon the linear equation Y=Xm+n, where m and n are derived from the given ranges. Rather than refer to the ranges as min and max, it would be better to refer to them as 1 and 2. So the formula would be:
Y = (((X - x1) ...